Java lang byte size

Java lang byte size

The Byte class wraps a value of primitive type byte in an object. An object of type Byte contains a single field whose type is byte . In addition, this class provides several methods for converting a byte to a String and a String to a byte , as well as other constants and methods useful when dealing with a byte .

Field Summary

Constructor Summary

Constructs a newly allocated Byte object that represents the byte value indicated by the String parameter.

Method Summary

Returns a Byte object holding the value extracted from the specified String when parsed with the radix given by the second argument.

Methods inherited from class java.lang.Object

Field Detail

MIN_VALUE

public static final byte MIN_VALUE

MAX_VALUE

public static final byte MAX_VALUE

TYPE

SIZE

public static final int SIZE

BYTES

public static final int BYTES

Constructor Detail

Byte

Byte

public Byte(String s) throws NumberFormatException

Constructs a newly allocated Byte object that represents the byte value indicated by the String parameter. The string is converted to a byte value in exactly the manner used by the parseByte method for radix 10.

Method Detail

toString

valueOf

Returns a Byte instance representing the specified byte value. If a new Byte instance is not required, this method should generally be used in preference to the constructor Byte(byte) , as this method is likely to yield significantly better space and time performance since all byte values are cached.

parseByte

public static byte parseByte(String s, int radix) throws NumberFormatException

• The first argument is null or is a string of length zero.
• The radix is either smaller than Character.MIN_RADIX or larger than Character.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 byte .

parseByte

public static byte parseByte(String s) throws NumberFormatException

Parses the string argument as a signed decimal byte . 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 byte value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseByte(java.lang.String, int) method.

valueOf

public static Byte valueOf(String s, int radix) throws NumberFormatException

Returns a Byte object holding the value extracted from the specified String when parsed with the radix given by the second argument. The first argument is interpreted as representing a signed byte in the radix specified by the second argument, exactly as if the argument were given to the parseByte(java.lang.String, int) method. The result is a Byte object that represents the byte value specified by the string. In other words, this method returns a Byte object equal to the value of:

valueOf

public static Byte valueOf(String s) throws NumberFormatException

Returns a Byte object holding the value given by the specified String . The argument is interpreted as representing a signed decimal byte , exactly as if the argument were given to the parseByte(java.lang.String) method. The result is a Byte object that represents the byte value specified by the string. In other words, this method returns a Byte object equal to the value of:

decode

public static Byte decode(String nm) throws NumberFormatException

Decodes a String into a Byte . Accepts decimal, hexadecimal, and octal numbers given by the following grammar:

DecodableString: Sign_opt DecimalNumeral Sign_opt 0x HexDigits Sign_opt 0X HexDigits Sign_opt # HexDigits Sign_opt 0 OctalDigits Sign: — +

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. The sequence of characters following an optional sign and/or radix specifier (» 0x «, » 0X «, » # «, or leading zero) is parsed as by the Byte.parseByte method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or a NumberFormatException will be thrown. The result is negated if first character of the specified String is the minus sign. No whitespace characters are permitted in the String .

byteValue

shortValue

Источник

Class Byte

The Byte class wraps a value of primitive type byte in an object. An object of type Byte contains a single field whose type is byte .

In addition, this class provides several methods for converting a byte to a String and a String to a byte , as well as other constants and methods useful when dealing with a byte .

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Field Summary

Constructor Summary

Method Summary

Returns a Byte object holding the value extracted from the specified String when parsed with the radix given by the second argument.

Methods declared in class java.lang.Object

Field Details

MIN_VALUE

MAX_VALUE

TYPE

SIZE

BYTES

Constructor Details

Byte

It is rarely appropriate to use this constructor. The static factory valueOf(byte) is generally a better choice, as it is likely to yield significantly better space and time performance.

Byte

It is rarely appropriate to use this constructor. Use parseByte(String) to convert a string to a byte primitive, or use valueOf(String) to convert a string to a Byte object.

Constructs a newly allocated Byte object that represents the byte value indicated by the String parameter. The string is converted to a byte value in exactly the manner used by the parseByte method for radix 10.

Method Details

toString

describeConstable

valueOf

Returns a Byte instance representing the specified byte value. If a new Byte instance is not required, this method should generally be used in preference to the constructor Byte(byte) , as this method is likely to yield significantly better space and time performance since all byte values are cached.

parseByte

• The first argument is null or is a string of length zero.
• The radix is either smaller than Character.MIN_RADIX or larger than Character.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 byte .

parseByte

Parses the string argument as a signed decimal byte . 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 byte value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseByte(java.lang.String, int) method.

valueOf

Returns a Byte object holding the value extracted from the specified String when parsed with the radix given by the second argument. The first argument is interpreted as representing a signed byte in the radix specified by the second argument, exactly as if the argument were given to the parseByte(java.lang.String, int) method. The result is a Byte object that represents the byte value specified by the string. In other words, this method returns a Byte object equal to the value of:

valueOf

Returns a Byte object holding the value given by the specified String . The argument is interpreted as representing a signed decimal byte , exactly as if the argument were given to the parseByte(java.lang.String) method. The result is a Byte object that represents the byte value specified by the string. In other words, this method returns a Byte object equal to the value of:

decode

Decodes a String into a Byte . Accepts decimal, hexadecimal, and octal numbers given by the following grammar:

DecodableString: Sign_opt DecimalNumeral Sign_opt 0x HexDigits Sign_opt 0X HexDigits Sign_opt # HexDigits Sign_opt 0 OctalDigits Sign: — +

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. The sequence of characters following an optional sign and/or radix specifier (» 0x «, » 0X «, » # «, or leading zero) is parsed as by the Byte.parseByte method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or a NumberFormatException will be thrown. The result is negated if first character of the specified String is the minus sign. No whitespace characters are permitted in the String .

byteValue

shortValue

intValue

longValue

floatValue

doubleValue

toString

Returns a String object representing this Byte ‘s value. The value is converted to signed decimal representation and returned as a string, exactly as if the byte value were given as an argument to the toString(byte) method.

hashCode

hashCode

equals

Compares this object to the specified object. The result is true if and only if the argument is not null and is a Byte object that contains the same byte value as this object.

compareTo

compare

Byte.valueOf(x).compareTo(Byte.valueOf(y))

compareUnsigned

toUnsignedInt

Converts the argument to an int by an unsigned conversion. In an unsigned conversion to an int , the high-order 24 bits of the int are zero and the low-order 8 bits are equal to the bits of the byte argument. Consequently, zero and positive byte values are mapped to a numerically equal int value and negative byte values are mapped to an int value equal to the input plus 2 8 .

toUnsignedLong

Converts the argument to a long by an unsigned conversion. In an unsigned conversion to a long , the high-order 56 bits of the long are zero and the low-order 8 bits are equal to the bits of the byte argument. Consequently, zero and positive byte values are mapped to a numerically equal long value and negative byte values are mapped to a long value equal to the input plus 2 8 .

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