- java.lang.Object
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- java.lang.Number
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- java.lang.Integer
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- All Implemented Interfaces:
Serializable,Comparable<Integer>
public final class Integer extends Number implements Comparable<Integer>
TheIntegerclass wraps a value of the primitive typeintin an object. An object of typeIntegercontains a single field whose type isint.In addition, this class provides several methods for converting an
intto aStringand aStringto anint, as well as other constants and methods useful when dealing with anint.Implementation note: The implementations of the "bit twiddling" methods (such as
highestOneBitandnumberOfTrailingZeros) are based on material from Henry S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002).- Since:
- 1.0
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static intBYTESThe number of bytes used to represent anintvalue in two's complement binary form.static intMAX_VALUEA constant holding the maximum value anintcan have, 231-1.static intMIN_VALUEA constant holding the minimum value anintcan have, -231.static intSIZEThe number of bits used to represent anintvalue in two's complement binary form.static Class<Integer>TYPETheClassinstance representing the primitive typeint.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static intbitCount(int i)Returns the number of one-bits in the two's complement binary representation of the specifiedintvalue.bytebyteValue()Returns the value of thisIntegeras abyteafter a narrowing primitive conversion.static intcompare(int x, int y)Compares twointvalues numerically.intcompareTo(Integer anotherInteger)Compares twoIntegerobjects numerically.static intcompareUnsigned(int x, int y)Compares twointvalues numerically treating the values as unsigned.static Integerdecode(String nm)Decodes aStringinto anInteger.static intdivideUnsigned(int dividend, int divisor)Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.doubledoubleValue()Returns the value of thisIntegeras adoubleafter a widening primitive conversion.booleanequals(Object obj)Compares this object to the specified object.floatfloatValue()Returns the value of thisIntegeras afloatafter a widening primitive conversion.static IntegergetInteger(String nm)Determines the integer value of the system property with the specified name.static IntegergetInteger(String nm, int val)Determines the integer value of the system property with the specified name.static IntegergetInteger(String nm, Integer val)Returns the integer value of the system property with the specified name.inthashCode()Returns a hash code for thisInteger.static inthashCode(int value)Returns a hash code for anintvalue; compatible withInteger.hashCode().static inthighestOneBit(int i)Returns anintvalue with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedintvalue.intintValue()Returns the value of thisIntegeras anint.longlongValue()Returns the value of thisIntegeras alongafter a widening primitive conversion.static intlowestOneBit(int i)Returns anintvalue with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedintvalue.static intmax(int a, int b)Returns the greater of twointvalues as if by callingMath.max.static intmin(int a, int b)Returns the smaller of twointvalues as if by callingMath.min.static intnumberOfLeadingZeros(int i)Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedintvalue.static intnumberOfTrailingZeros(int i)Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedintvalue.static intparseInt(CharSequence s, int beginIndex, int endIndex, int radix)Parses theCharSequenceargument as a signedintin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.static intparseInt(String s)Parses the string argument as a signed decimal integer.static intparseInt(String s, int radix)Parses the string argument as a signed integer in the radix specified by the second argument.static intparseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix)Parses theCharSequenceargument as an unsignedintin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.static intparseUnsignedInt(String s)Parses the string argument as an unsigned decimal integer.static intparseUnsignedInt(String s, int radix)Parses the string argument as an unsigned integer in the radix specified by the second argument.static intremainderUnsigned(int dividend, int divisor)Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.static intreverse(int i)Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedintvalue.static intreverseBytes(int i)Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedintvalue.static introtateLeft(int i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedintvalue left by the specified number of bits.static introtateRight(int i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedintvalue right by the specified number of bits.shortshortValue()Returns the value of thisIntegeras ashortafter a narrowing primitive conversion.static intsignum(int i)Returns the signum function of the specifiedintvalue.static intsum(int a, int b)Adds two integers together as per the + operator.static StringtoBinaryString(int i)Returns a string representation of the integer argument as an unsigned integer in base 2.static StringtoHexString(int i)Returns a string representation of the integer argument as an unsigned integer in base 16.static StringtoOctalString(int i)Returns a string representation of the integer argument as an unsigned integer in base 8.StringtoString()Returns aStringobject representing thisInteger's value.static StringtoString(int i)Returns aStringobject representing the specified integer.static StringtoString(int i, int radix)Returns a string representation of the first argument in the radix specified by the second argument.static longtoUnsignedLong(int x)Converts the argument to alongby an unsigned conversion.static StringtoUnsignedString(int i)Returns a string representation of the argument as an unsigned decimal value.static StringtoUnsignedString(int i, int radix)Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.static IntegervalueOf(int i)Returns anIntegerinstance representing the specifiedintvalue.static IntegervalueOf(String s)Returns anIntegerobject holding the value of the specifiedString.static IntegervalueOf(String s, int radix)Returns anIntegerobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument.
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Field Detail
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MIN_VALUE
@Native public static final int MIN_VALUE
A constant holding the minimum value anintcan have, -231.- See Also:
- Constant Field Values
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MAX_VALUE
@Native public static final int MAX_VALUE
A constant holding the maximum value anintcan have, 231-1.- See Also:
- Constant Field Values
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TYPE
public static final Class<Integer> TYPE
TheClassinstance representing the primitive typeint.- Since:
- 1.1
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SIZE
@Native public static final int SIZE
The number of bits used to represent anintvalue in two's complement binary form.- Since:
- 1.5
- See Also:
- Constant Field Values
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BYTES
public static final int BYTES
The number of bytes used to represent anintvalue in two's complement binary form.- Since:
- 1.8
- See Also:
- Constant Field Values
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Constructor Detail
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Integer
@Deprecated(since="9") public Integer(int value)
Deprecated.It is rarely appropriate to use this constructor. The static factoryvalueOf(int)is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocatedIntegerobject that represents the specifiedintvalue.- Parameters:
value- the value to be represented by theIntegerobject.
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Integer
@Deprecated(since="9") public Integer(String s) throws NumberFormatException
Deprecated.It is rarely appropriate to use this constructor. UseparseInt(String)to convert a string to aintprimitive, or usevalueOf(String)to convert a string to anIntegerobject.Constructs a newly allocatedIntegerobject that represents theintvalue indicated by theStringparameter. The string is converted to anintvalue in exactly the manner used by theparseIntmethod for radix 10.- Parameters:
s- theStringto be converted to anInteger.- Throws:
NumberFormatException- if theStringdoes not contain a parsable integer.
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Method Detail
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toString
public static String toString(int i, int radix)
Returns a string representation of the first argument in the radix specified by the second argument.If the radix is smaller than
Character.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10is used instead.If the first argument is negative, the first element of the result is the ASCII minus character
'-'('\u002D'). If the first argument is not negative, no sign character appears in the result.The remaining characters of the result represent the magnitude of the first argument. If the magnitude is zero, it is represented by a single zero character
'0'('\u0030'); otherwise, the first character of the representation of the magnitude will not be the zero character. The following ASCII characters are used as digits:
These are0123456789abcdefghijklmnopqrstuvwxyz'\u0030'through'\u0039'and'\u0061'through'\u007A'. Ifradixis N, then the first N of these characters are used as radix-N digits in the order shown. Thus, the digits for hexadecimal (radix 16) are0123456789abcdef. If uppercase letters are desired, theString.toUpperCase()method may be called on the result:Integer.toString(n, 16).toUpperCase()- Parameters:
i- an integer to be converted to a string.radix- the radix to use in the string representation.- Returns:
- a string representation of the argument in the specified radix.
- See Also:
Character.MAX_RADIX,Character.MIN_RADIX
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toUnsignedString
public static String toUnsignedString(int i, int radix)
Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.If the radix is smaller than
Character.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10is used instead.Note that since the first argument is treated as an unsigned value, no leading sign character is printed.
If the magnitude is zero, it is represented by a single zero character
'0'('\u0030'); otherwise, the first character of the representation of the magnitude will not be the zero character.The behavior of radixes and the characters used as digits are the same as
toString.- Parameters:
i- an integer to be converted to an unsigned string.radix- the radix to use in the string representation.- Returns:
- an unsigned string representation of the argument in the specified radix.
- Since:
- 1.8
- See Also:
toString(int, int)
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toHexString
public static String toHexString(int i)
Returns a string representation of the integer argument as an unsigned integer in base 16.The unsigned integer value is the argument plus 232 if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in hexadecimal (base 16) with no extra leading
0s.The value of the argument can be recovered from the returned string
sby callingInteger.parseUnsignedInt(s, 16).If the unsigned magnitude is zero, it is represented by a single zero character
'0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as hexadecimal digits:
These are the characters0123456789abcdef'\u0030'through'\u0039'and'\u0061'through'\u0066'. If uppercase letters are desired, theString.toUpperCase()method may be called on the result:Integer.toHexString(n).toUpperCase()- Parameters:
i- an integer to be converted to a string.- Returns:
- the string representation of the unsigned integer value represented by the argument in hexadecimal (base 16).
- Since:
- 1.0.2
- See Also:
parseUnsignedInt(String, int),toUnsignedString(int, int)
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toOctalString
public static String toOctalString(int i)
Returns a string representation of the integer argument as an unsigned integer in base 8.The unsigned integer value is the argument plus 232 if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in octal (base 8) with no extra leading
0s.The value of the argument can be recovered from the returned string
sby callingInteger.parseUnsignedInt(s, 8).If the unsigned magnitude is zero, it is represented by a single zero character
'0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as octal digits:
These are the characters01234567'\u0030'through'\u0037'.- Parameters:
i- an integer to be converted to a string.- Returns:
- the string representation of the unsigned integer value represented by the argument in octal (base 8).
- Since:
- 1.0.2
- See Also:
parseUnsignedInt(String, int),toUnsignedString(int, int)
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toBinaryString
public static String toBinaryString(int i)
Returns a string representation of the integer argument as an unsigned integer in base 2.The unsigned integer value is the argument plus 232 if the argument is negative; otherwise it is equal to the argument. This value is converted to a string of ASCII digits in binary (base 2) with no extra leading
0s.The value of the argument can be recovered from the returned string
sby callingInteger.parseUnsignedInt(s, 2).If the unsigned magnitude is zero, it is represented by a single zero character
'0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The characters'0'('\u0030') and'1'('\u0031') are used as binary digits.- Parameters:
i- an integer to be converted to a string.- Returns:
- the string representation of the unsigned integer value represented by the argument in binary (base 2).
- Since:
- 1.0.2
- See Also:
parseUnsignedInt(String, int),toUnsignedString(int, int)
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toString
public static String toString(int i)
Returns aStringobject representing the specified integer. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and radix 10 were given as arguments to thetoString(int, int)method.- Parameters:
i- an integer to be converted.- Returns:
- a string representation of the argument in base 10.
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toUnsignedString
public static String toUnsignedString(int i)
Returns a string representation of the argument as an unsigned decimal value. The argument is converted to unsigned decimal representation and returned as a string exactly as if the argument and radix 10 were given as arguments to thetoUnsignedString(int, int)method.- Parameters:
i- an integer to be converted to an unsigned string.- Returns:
- an unsigned string representation of the argument.
- Since:
- 1.8
- See Also:
toUnsignedString(int, int)
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parseInt
public static int parseInt(String s, int radix) throws NumberFormatException
Parses the string argument as a signed integer in the radix specified by the second argument. The characters in the string must all be digits of the specified radix (as determined by whetherCharacter.digit(char, int)returns a nonnegative value), except that the first character may be an ASCII minus sign'-'('\u002D') to indicate a negative value or an ASCII plus sign'+'('\u002B') to indicate a positive value. The resulting integer value is returned.An exception of type
NumberFormatExceptionis thrown if any of the following situations occurs:- The first argument is
nullor is a string of length zero. - The radix is either smaller than
Character.MIN_RADIXor larger thanCharacter.MAX_RADIX. - Any character of the string is not a digit of the specified
radix, except that the first character may be a minus sign
'-'('\u002D') or plus sign'+'('\u002B') provided that the string is longer than length 1. - The value represented by the string is not a value of type
int.
Examples:
parseInt("0", 10) returns 0 parseInt("473", 10) returns 473 parseInt("+42", 10) returns 42 parseInt("-0", 10) returns 0 parseInt("-FF", 16) returns -255 parseInt("1100110", 2) returns 102 parseInt("2147483647", 10) returns 2147483647 parseInt("-2147483648", 10) returns -2147483648 parseInt("2147483648", 10) throws a NumberFormatException parseInt("99", 8) throws a NumberFormatException parseInt("Kona", 10) throws a NumberFormatException parseInt("Kona", 27) returns 411787- Parameters:
s- theStringcontaining the integer representation to be parsedradix- the radix to be used while parsings.- Returns:
- the integer represented by the string argument in the specified radix.
- Throws:
NumberFormatException- if theStringdoes not contain a parsableint.
- The first argument is
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parseInt
public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
Parses theCharSequenceargument as a signedintin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.The method does not take steps to guard against the
CharSequencebeing mutated while parsing.- Parameters:
s- theCharSequencecontaining theintrepresentation to be parsedbeginIndex- the beginning index, inclusive.endIndex- the ending index, exclusive.radix- the radix to be used while parsings.- Returns:
- the signed
intrepresented by the subsequence in the specified radix. - Throws:
NullPointerException- ifsis null.IndexOutOfBoundsException- ifbeginIndexis negative, or ifbeginIndexis greater thanendIndexor ifendIndexis greater thans.length().NumberFormatException- if theCharSequencedoes not contain a parsableintin the specifiedradix, or ifradixis either smaller thanCharacter.MIN_RADIXor larger thanCharacter.MAX_RADIX.- Since:
- 9
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parseInt
public static int parseInt(String s) throws NumberFormatException
Parses the string argument as a signed decimal integer. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign'-'('\u002D') to indicate a negative value or an ASCII plus sign'+'('\u002B') to indicate a positive value. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to theparseInt(java.lang.String, int)method.- Parameters:
s- aStringcontaining theintrepresentation to be parsed- Returns:
- the integer value represented by the argument in decimal.
- Throws:
NumberFormatException- if the string does not contain a parsable integer.
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parseUnsignedInt
public static int parseUnsignedInt(String s, int radix) throws NumberFormatException
Parses the string argument as an unsigned integer in the radix specified by the second argument. An unsigned integer maps the values usually associated with negative numbers to positive numbers larger thanMAX_VALUE. The characters in the string must all be digits of the specified radix (as determined by whetherCharacter.digit(char, int)returns a nonnegative value), except that the first character may be an ASCII plus sign'+'('\u002B'). The resulting integer value is returned.An exception of type
NumberFormatExceptionis thrown if any of the following situations occurs:- The first argument is
nullor is a string of length zero. - The radix is either smaller than
Character.MIN_RADIXor larger thanCharacter.MAX_RADIX. - Any character of the string is not a digit of the specified
radix, except that the first character may be a plus sign
'+'('\u002B') provided that the string is longer than length 1. - The value represented by the string is larger than the
largest unsigned
int, 232-1.
- Parameters:
s- theStringcontaining the unsigned integer representation to be parsedradix- the radix to be used while parsings.- Returns:
- the integer represented by the string argument in the specified radix.
- Throws:
NumberFormatException- if theStringdoes not contain a parsableint.- Since:
- 1.8
- The first argument is
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parseUnsignedInt
public static int parseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
Parses theCharSequenceargument as an unsignedintin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.The method does not take steps to guard against the
CharSequencebeing mutated while parsing.- Parameters:
s- theCharSequencecontaining the unsignedintrepresentation to be parsedbeginIndex- the beginning index, inclusive.endIndex- the ending index, exclusive.radix- the radix to be used while parsings.- Returns:
- the unsigned
intrepresented by the subsequence in the specified radix. - Throws:
NullPointerException- ifsis null.IndexOutOfBoundsException- ifbeginIndexis negative, or ifbeginIndexis greater thanendIndexor ifendIndexis greater thans.length().NumberFormatException- if theCharSequencedoes not contain a parsable unsignedintin the specifiedradix, or ifradixis either smaller thanCharacter.MIN_RADIXor larger thanCharacter.MAX_RADIX.- Since:
- 9
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parseUnsignedInt
public static int parseUnsignedInt(String s) throws NumberFormatException
Parses the string argument as an unsigned decimal integer. The characters in the string must all be decimal digits, except that the first character may be an ASCII plus sign'+'('\u002B'). The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to theparseUnsignedInt(java.lang.String, int)method.- Parameters:
s- aStringcontaining the unsignedintrepresentation to be parsed- Returns:
- the unsigned integer value represented by the argument in decimal.
- Throws:
NumberFormatException- if the string does not contain a parsable unsigned integer.- Since:
- 1.8
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valueOf
public static Integer valueOf(String s, int radix) throws NumberFormatException
Returns anIntegerobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument. The first argument is interpreted as representing a signed integer in the radix specified by the second argument, exactly as if the arguments were given to theparseInt(java.lang.String, int)method. The result is anIntegerobject that represents the integer value specified by the string.In other words, this method returns an
Integerobject equal to the value of:new Integer(Integer.parseInt(s, radix))- Parameters:
s- the string to be parsed.radix- the radix to be used in interpretings- Returns:
- an
Integerobject holding the value represented by the string argument in the specified radix. - Throws:
NumberFormatException- if theStringdoes not contain a parsableint.
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valueOf
public static Integer valueOf(String s) throws NumberFormatException
Returns anIntegerobject holding the value of the specifiedString. The argument is interpreted as representing a signed decimal integer, exactly as if the argument were given to theparseInt(java.lang.String)method. The result is anIntegerobject that represents the integer value specified by the string.In other words, this method returns an
Integerobject equal to the value of:new Integer(Integer.parseInt(s))- Parameters:
s- the string to be parsed.- Returns:
- an
Integerobject holding the value represented by the string argument. - Throws:
NumberFormatException- if the string cannot be parsed as an integer.
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valueOf
public static Integer valueOf(int i)
Returns anIntegerinstance representing the specifiedintvalue. If a newIntegerinstance is not required, this method should generally be used in preference to the constructorInteger(int), as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range -128 to 127, inclusive, and may cache other values outside of this range.- Parameters:
i- anintvalue.- Returns:
- an
Integerinstance representingi. - Since:
- 1.5
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byteValue
public byte byteValue()
Returns the value of thisIntegeras abyteafter a narrowing primitive conversion.
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shortValue
public short shortValue()
Returns the value of thisIntegeras ashortafter a narrowing primitive conversion.- Overrides:
shortValuein classNumber- Returns:
- the numeric value represented by this object after conversion
to type
short. - See The Java™ Language Specification:
- 5.1.3 Narrowing Primitive Conversions
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intValue
public int intValue()
Returns the value of thisIntegeras anint.
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longValue
public long longValue()
Returns the value of thisIntegeras alongafter a widening primitive conversion.- Specified by:
longValuein classNumber- Returns:
- the numeric value represented by this object after conversion
to type
long. - See Also:
toUnsignedLong(int)- See The Java™ Language Specification:
- 5.1.2 Widening Primitive Conversions
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floatValue
public float floatValue()
Returns the value of thisIntegeras afloatafter a widening primitive conversion.- Specified by:
floatValuein classNumber- Returns:
- the numeric value represented by this object after conversion
to type
float. - See The Java™ Language Specification:
- 5.1.2 Widening Primitive Conversions
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doubleValue
public double doubleValue()
Returns the value of thisIntegeras adoubleafter a widening primitive conversion.- Specified by:
doubleValuein classNumber- Returns:
- the numeric value represented by this object after conversion
to type
double. - See The Java™ Language Specification:
- 5.1.2 Widening Primitive Conversions
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toString
public String toString()
Returns aStringobject representing thisInteger's value. The value is converted to signed decimal representation and returned as a string, exactly as if the integer value were given as an argument to thetoString(int)method.
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hashCode
public int hashCode()
Returns a hash code for thisInteger.- Overrides:
hashCodein classObject- Returns:
- a hash code value for this object, equal to the
primitive
intvalue represented by thisIntegerobject. - See Also:
Object.equals(java.lang.Object),System.identityHashCode(java.lang.Object)
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hashCode
public static int hashCode(int value)
Returns a hash code for anintvalue; compatible withInteger.hashCode().- Parameters:
value- the value to hash- Returns:
- a hash code value for an
intvalue. - Since:
- 1.8
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equals
public boolean equals(Object obj)
Compares this object to the specified object. The result istrueif and only if the argument is notnulland is anIntegerobject that contains the sameintvalue as this object.- Overrides:
equalsin classObject- Parameters:
obj- the object to compare with.- Returns:
trueif the objects are the same;falseotherwise.- See Also:
Object.hashCode(),HashMap
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getInteger
public static Integer getInteger(String nm)
Determines the integer value of the system property with the specified name.The first argument is treated as the name of a system property. System properties are accessible through the
System.getProperty(java.lang.String)method. The string value of this property is then interpreted as an integer value using the grammar supported bydecodeand anIntegerobject representing this value is returned.If there is no property with the specified name, if the specified name is empty or
null, or if the property does not have the correct numeric format, thennullis returned.In other words, this method returns an
Integerobject equal to the value of:getInteger(nm, null)- Parameters:
nm- property name.- Returns:
- the
Integervalue of the property. - Throws:
SecurityException- for the same reasons asSystem.getProperty- See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
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getInteger
public static Integer getInteger(String nm, int val)
Determines the integer value of the system property with the specified name.The first argument is treated as the name of a system property. System properties are accessible through the
System.getProperty(java.lang.String)method. The string value of this property is then interpreted as an integer value using the grammar supported bydecodeand anIntegerobject representing this value is returned.The second argument is the default value. An
Integerobject that represents the value of the second argument is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty ornull.In other words, this method returns an
Integerobject equal to the value of:
but in practice it may be implemented in a manner such as:getInteger(nm, new Integer(val))
to avoid the unnecessary allocation of anInteger result = getInteger(nm, null); return (result == null) ? new Integer(val) : result;
Integerobject when the default value is not needed.- Parameters:
nm- property name.val- default value.- Returns:
- the
Integervalue of the property. - Throws:
SecurityException- for the same reasons asSystem.getProperty- See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
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getInteger
public static Integer getInteger(String nm, Integer val)
Returns the integer value of the system property with the specified name. The first argument is treated as the name of a system property. System properties are accessible through theSystem.getProperty(java.lang.String)method. The string value of this property is then interpreted as an integer value, as per thedecodemethod, and anIntegerobject representing this value is returned; in summary:- If the property value begins with the two ASCII characters
0xor the ASCII character#, not followed by a minus sign, then the rest of it is parsed as a hexadecimal integer exactly as by the methodvalueOf(java.lang.String, int)with radix 16. - If the property value begins with the ASCII character
0followed by another character, it is parsed as an octal integer exactly as by the methodvalueOf(java.lang.String, int)with radix 8. - Otherwise, the property value is parsed as a decimal integer
exactly as by the method
valueOf(java.lang.String, int)with radix 10.
The second argument is the default value. The default value is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty or
null.- Parameters:
nm- property name.val- default value.- Returns:
- the
Integervalue of the property. - Throws:
SecurityException- for the same reasons asSystem.getProperty- See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
- If the property value begins with the two ASCII characters
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decode
public static Integer decode(String nm) throws NumberFormatException
Decodes aStringinto anInteger. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
DecimalNumeral, HexDigits, and OctalDigits are as defined in section 3.10.1 of The Java™ Language Specification, except that underscores are not accepted between digits.- DecodableString:
- Signopt DecimalNumeral
- Signopt
0xHexDigits- Signopt
0XHexDigits- Signopt
#HexDigits- Signopt
0OctalDigits - Signopt
- Sign:
-+
The sequence of characters following an optional sign and/or radix specifier ("
0x", "0X", "#", or leading zero) is parsed as by theInteger.parseIntmethod with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or aNumberFormatExceptionwill be thrown. The result is negated if first character of the specifiedStringis the minus sign. No whitespace characters are permitted in theString.- Parameters:
nm- theStringto decode.- Returns:
- an
Integerobject holding theintvalue represented bynm - Throws:
NumberFormatException- if theStringdoes not contain a parsable integer.- See Also:
parseInt(java.lang.String, int)
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compareTo
public int compareTo(Integer anotherInteger)
Compares twoIntegerobjects numerically.- Specified by:
compareToin interfaceComparable<Integer>- Parameters:
anotherInteger- theIntegerto be compared.- Returns:
- the value
0if thisIntegeris equal to the argumentInteger; a value less than0if thisIntegeris numerically less than the argumentInteger; and a value greater than0if thisIntegeris numerically greater than the argumentInteger(signed comparison). - Since:
- 1.2
-
compare
public static int compare(int x, int y)Compares twointvalues numerically. The value returned is identical to what would be returned by:Integer.valueOf(x).compareTo(Integer.valueOf(y))- Parameters:
x- the firstintto comparey- the secondintto compare- Returns:
- the value
0ifx == y; a value less than0ifx < y; and a value greater than0ifx > y - Since:
- 1.7
-
compareUnsigned
public static int compareUnsigned(int x, int y)Compares twointvalues numerically treating the values as unsigned.- Parameters:
x- the firstintto comparey- the secondintto compare- Returns:
- the value
0ifx == y; a value less than0ifx < yas unsigned values; and a value greater than0ifx > yas unsigned values - Since:
- 1.8
-
toUnsignedLong
public static long toUnsignedLong(int x)
Converts the argument to alongby an unsigned conversion. In an unsigned conversion to along, the high-order 32 bits of thelongare zero and the low-order 32 bits are equal to the bits of the integer argument. Consequently, zero and positiveintvalues are mapped to a numerically equallongvalue and negativeintvalues are mapped to alongvalue equal to the input plus 232.- Parameters:
x- the value to convert to an unsignedlong- Returns:
- the argument converted to
longby an unsigned conversion - Since:
- 1.8
-
divideUnsigned
public static int divideUnsigned(int dividend, int divisor)Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.Note that in two's complement arithmetic, the three other basic arithmetic operations of add, subtract, and multiply are bit-wise identical if the two operands are regarded as both being signed or both being unsigned. Therefore separate
addUnsigned, etc. methods are not provided.- Parameters:
dividend- the value to be divideddivisor- the value doing the dividing- Returns:
- the unsigned quotient of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
remainderUnsigned(int, int)
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remainderUnsigned
public static int remainderUnsigned(int dividend, int divisor)Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.- Parameters:
dividend- the value to be divideddivisor- the value doing the dividing- Returns:
- the unsigned remainder of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
divideUnsigned(int, int)
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highestOneBit
public static int highestOneBit(int i)
Returns anintvalue with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedintvalue. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.- Parameters:
i- the value whose highest one bit is to be computed- Returns:
- an
intvalue with a single one-bit, in the position of the highest-order one-bit in the specified value, or zero if the specified value is itself equal to zero. - Since:
- 1.5
-
lowestOneBit
public static int lowestOneBit(int i)
Returns anintvalue with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedintvalue. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.- Parameters:
i- the value whose lowest one bit is to be computed- Returns:
- an
intvalue with a single one-bit, in the position of the lowest-order one-bit in the specified value, or zero if the specified value is itself equal to zero. - Since:
- 1.5
-
numberOfLeadingZeros
public static int numberOfLeadingZeros(int i)
Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedintvalue. Returns 32 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.Note that this method is closely related to the logarithm base 2. For all positive
intvalues x:- floor(log2(x)) =
31 - numberOfLeadingZeros(x) - ceil(log2(x)) =
32 - numberOfLeadingZeros(x - 1)
- Parameters:
i- the value whose number of leading zeros is to be computed- Returns:
- the number of zero bits preceding the highest-order
("leftmost") one-bit in the two's complement binary representation
of the specified
intvalue, or 32 if the value is equal to zero. - Since:
- 1.5
- floor(log2(x)) =
-
numberOfTrailingZeros
public static int numberOfTrailingZeros(int i)
Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedintvalue. Returns 32 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.- Parameters:
i- the value whose number of trailing zeros is to be computed- Returns:
- the number of zero bits following the lowest-order ("rightmost")
one-bit in the two's complement binary representation of the
specified
intvalue, or 32 if the value is equal to zero. - Since:
- 1.5
-
bitCount
public static int bitCount(int i)
Returns the number of one-bits in the two's complement binary representation of the specifiedintvalue. This function is sometimes referred to as the population count.- Parameters:
i- the value whose bits are to be counted- Returns:
- the number of one-bits in the two's complement binary
representation of the specified
intvalue. - Since:
- 1.5
-
rotateLeft
public static int rotateLeft(int i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedintvalue left by the specified number of bits. (Bits shifted out of the left hand, or high-order, side reenter on the right, or low-order.)Note that left rotation with a negative distance is equivalent to right rotation:
rotateLeft(val, -distance) == rotateRight(val, distance). Note also that rotation by any multiple of 32 is a no-op, so all but the last five bits of the rotation distance can be ignored, even if the distance is negative:rotateLeft(val, distance) == rotateLeft(val, distance & 0x1F).- Parameters:
i- the value whose bits are to be rotated leftdistance- the number of bit positions to rotate left- Returns:
- the value obtained by rotating the two's complement binary
representation of the specified
intvalue left by the specified number of bits. - Since:
- 1.5
-
rotateRight
public static int rotateRight(int i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedintvalue right by the specified number of bits. (Bits shifted out of the right hand, or low-order, side reenter on the left, or high-order.)Note that right rotation with a negative distance is equivalent to left rotation:
rotateRight(val, -distance) == rotateLeft(val, distance). Note also that rotation by any multiple of 32 is a no-op, so all but the last five bits of the rotation distance can be ignored, even if the distance is negative:rotateRight(val, distance) == rotateRight(val, distance & 0x1F).- Parameters:
i- the value whose bits are to be rotated rightdistance- the number of bit positions to rotate right- Returns:
- the value obtained by rotating the two's complement binary
representation of the specified
intvalue right by the specified number of bits. - Since:
- 1.5
-
reverse
public static int reverse(int i)
Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedintvalue.- Parameters:
i- the value to be reversed- Returns:
- the value obtained by reversing order of the bits in the
specified
intvalue. - Since:
- 1.5
-
signum
public static int signum(int i)
Returns the signum function of the specifiedintvalue. (The return value is -1 if the specified value is negative; 0 if the specified value is zero; and 1 if the specified value is positive.)- Parameters:
i- the value whose signum is to be computed- Returns:
- the signum function of the specified
intvalue. - Since:
- 1.5
-
reverseBytes
public static int reverseBytes(int i)
Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedintvalue.- Parameters:
i- the value whose bytes are to be reversed- Returns:
- the value obtained by reversing the bytes in the specified
intvalue. - Since:
- 1.5
-
sum
public static int sum(int a, int b)Adds two integers together as per the + operator.- Parameters:
a- the first operandb- the second operand- Returns:
- the sum of
aandb - Since:
- 1.8
- See Also:
BinaryOperator
-
max
public static int max(int a, int b)Returns the greater of twointvalues as if by callingMath.max.- Parameters:
a- the first operandb- the second operand- Returns:
- the greater of
aandb - Since:
- 1.8
- See Also:
BinaryOperator
-
min
public static int min(int a, int b)Returns the smaller of twointvalues as if by callingMath.min.- Parameters:
a- the first operandb- the second operand- Returns:
- the smaller of
aandb - Since:
- 1.8
- See Also:
BinaryOperator
-
-