Java Data types

1. Integer (the default type is int)

　　If the data is larger than the range of type long, you can use the BigInteger class

Binary conversions:

Octal: 0 Opening
Hex: 0x or 0X start

Integer.tobinarystring (); //Convert to binary

Integer.tooctalstring (); //Convert to octal

Integer.tohexstring (); //Convert to hex

Type conversions:

If the size of the data does not exceed the type representation range you want to convert, you can automatically transform it.

Long type:

Long a = 123456L //l preferably capitalized, otherwise easily and 1 confused

2. Float type (default type is double)

　　There are rounding errors in floating-point numbers, such as the use of the BigDecimal class if you want an exact number that does not produce rounding errors

　　Avoid using floating-point types when comparing number sizes

The wording of E:

314e-2 = 3.14 //indicates 314*10^ ( -2)

Float usage:

float a = 3.14F //F indicates floating-point constant is float type

3. Characters

\ //escape character for special characters such as output ' \ \

Java Data types