Constant && variable

Unchanged during program run: a, constant

Constant use:

 

 Second, the eight basic data types of variables:

Wherein data representing a type of eight bit Byte bits, the range (-2 ~ 2 ^ 7 ^ 7-1), a quarter of type int space, save space for a large array;

short type is (2 ^ 15 to 2 ^ 15-1);