Java, a total of eight basic data types:
4 kinds integer: int, short, long, byte.
Two kinds of floating-point type: float, double.
One kind of character types: char.
Type one kind represented true value: boolean.
[String is not a primitive data types. Learn C language students should know that the string is actually a char array]
For these data types, the most important thing is to know about their ranges, so that the actual definition of them, only without error.
Integer and floating-point value range:
| Types of | Byte length | Ranges |
| int | 4 bytes | -2 147 483 648 ~ 2 147 483 647 |
| short | 2 bytes | -32 768 ~ 32 767 |
| long | 8 bytes | -9 223 372 036 854 775 808 ~ 9 223 372 036 854 775 807 |
| byte | 1 byte | -128 ~ 127 |
| float | 4 bytes | About ± 3.402 823 47E + 38F (6 ~ 7 significant digits) |
| double | 8 bytes | About ± 1.797 693 134 862 315 70E + 308 (15 significant digits) |
char type
char type value to use single quotes, such as: 'A'.
Note: "A" and 'A' is not the same. "A" is a string of length 1, which this test, often appear.
boolean type
Only two types of boolean values: false and true, the logic used to determine the conditions.
Note: Integer and Boolean type can not be converted. In C or C ++ species, number of non-zero may represent true, may represent the number 0 false.
So in Java among the logical conditions can only be false or true. If you enter a number, not by compilation.