[Javase] Basic data type Object wrapper class

According to the Java Object-oriented principle, each basic type has a corresponding wrapper class

BYTE byte

Short Short

int Integer

Long Long

Boolean Boolean

float float

Double Double

Char Character

The most common function is the conversion of the base type to string string types

Turn into a string: wrapper object . toString ()

The string is converted to the base type: wrapper class . ValueOf ()

decimal-to-binary: Call integer.tobinarystring ()

Decimal to 16 binary: Call integer.tohexstring ()

Binary to decimal: Call integer.parseint ("binary", 2)

Hexadecimal to decimal: Call integer.parseint ("hex", 16)

Automatic Boxing

Integer x=4, numbers of type int are automatically boxed into an integer object

Automatic unpacking

X=x+2,anInteger object is automatically disassembled into an int type for calculation

When the value is within the byte range, no new space will be opened for the new feature

Integer a=128

Integer b=128

SYSO (a==b)// normal false at this time

Integer a=127

Integer b=127

SYSO (a==b)// special True at this time

[Javase] Basic data type Object wrapper class