变量类型和典型值范围，如下表中所示:
| 类型 | 典型字节数 | 典型的值范围 |
|---|---|---|
char |
1 | -128 ~ +127 或 0 ~ +255 |
unsigned char |
1 | 0 ~ +255 |
short |
2 | -32,768 ~ +32,767 |
unsigned short |
2 | 0 ~ +65,535 |
int |
2 或 4 | -32,768 ~ +32,767 或 -2,147,438,648 ~ +2,147,438,647 |
unsigned int |
4 | 0 ~ +65,535 或 0 ~ +4,294,967,295 |
long |
4 | -2,147,438,648 ~ +2,147,438,647 |
unsigned long |
4 | 0 ~ +4,294,967,295 |
long long |
8 | -9,223,372,036,854,775,808 ~ +9,223,372,036,854,775,807 |
unsigned long long |
8 | 0 ~ +18,446,744,073,709,551,615 |
float |
4 | +/-3.4E+/-38 (6位数) |
double |
8 | +/-1.7E+/-308 (15位数) |
long double |
12 | +/-1.2E+/-4932(19位数) |
