五、 运算号、表达式和语句
2.基本运算符
2.6 除法运算符:/
four = 12.0/3.0;
/* divide.c -- 演示除法 */
#include <stdio.h>
int main(void)
{
printf("integer division: 5/4 is %d// \n", 5 / 4);
printf("integer division: 6/3 is %d \n", 6 / 3);
printf("integer division: 7/4 is %d \n", 7 / 4);
printf("floating division: 7./4 is %1.2f \n", 7. / 4.);
printf("mixed division: 7./4 is %1.2f \n", 7. / 4);
return 0;
}
//integer division: 5/4 is 1
//integer division: 6/3 is 2
//integer division: 7/4 is 1
//floating division: 7./4 is 1.75
//mixed division: 7./4 is 1.75
2.7 运算符优先级
butter = 25.0 +60.0 * n / SCALE;
运算符 | 结合律 |
---|---|
() | 从左往右 |
+ -(一元) | 从右往左 |
* / | 从左往右 |
+ -(二元) | 从左往右 |
= | 从右往左 |
2.8 优先级和求值顺序
y = 6 * 12 +5 * 20;
/* rules.c -- 优先级测试 */
#include <stdio.h>
int main(void)
{
int top, score;
top = score = -(2 + 5) * 6 + (4 + 3 * (2 + 3));
printf("top = %d, score = %d\n", top, score);
return 0;
}