Java Data types

Java is a strongly typed language.

Java has a total of 8 basic types, of which 4 are shaped, 2 floating-point types, 1 are used to represent Unicode-encoded character cells, char and 1 are used to represent true and false Boolean types.

integer : In Java, the scope of the shaping is independent of the machine running Java code--addressing cross-platform, different-digit operating system issues.

Int:4 byte -2147483648~2147483647 ( just over 2 billion )

Short:2 bytes -32768~32767

Long:8 byte Very Large

Byte:1 bytes -128~127

1 normally the int is sufficient.

2 Long integer has a suffix l

3 Note Java does not have any unsigned type (unsigned type)

float type : float 4 bytes

Double 8 bytes

1 in most cases the double type is used, and the precision of the float type is difficult to meet

2 float type suffix f

3 floating-point value without suffix f (for example, 3.402) defaults to double type

4 Double type suffix D

Interesting thing: System.out.println (2.0-1.1); will print 0.8999999999999999 instead of 0.9 of people's imagination. The main reason is that the floating-point value is represented by a binary system, and the fractional 1/10 is not accurately represented in the binary system. So you need to use the BigDecimal class without error.

Java Data types