C语言的运算符大全

article/2025/7/16 1:13:31

C语言运算符

文末附运算符的优先表和ASCII表
一、算术运算符

加(+）减（—）乘（*）除（/）
模（余）运算符（%）：不允许出现浮点型，余数正负取决于被除数正负

#include <stdio.h>
int main() {int i, b, a, c;i= 4, b=3;a= i+b;c= i*a;float p, k;p= i/b;k= i%a;printf("a=%d,c=%d,p=%f,k=%f\n",a,c,p,k);return 0;
}[root@chenshuyi c]# ./o
a=7,c=28,p=1.000000,k=4.000000

自增（++i，–i；i++，i–）

#include <stdio.h>
int main() {int i;i= 4;printf("%d\n",++i);return 0;
}[root@chenshuyi c]# ./o
5#include <stdio.h>
int main() {int i;i= 4;printf("%d\n",i--);//printf("%d\n",i); 输出是return 0;
}[root@chenshuyi c]# ./o
4

二、关系运算符

大于(>）小于(<）等于(==）

#include <stdio.h>
int main() {int a, b, max;printf ("please enter a and b\n");scanf ("%d %d",&a, &b);if (a>b) max=a;if (a<b) max=b;if (a==b) max=a;printf ("max=%d\n",max);return 0;
}
[root@chenshuyi c]# ./o
please enter a and b
55 66
max=66
[root@chenshuyi c]# ./o
please enter a and b
44 44
max=44

小于或等于(<=）大于或等于(>=）不等于(!=）赋值(-=、+=、*=)；

#include<stdio.h>
int main(){int a = 10;a +=a *=a -=20;printf("%d\n",a);
}[root@chenshuyi c]# ./ass
200#include <stdio.h>
int main() {int a, b, max;printf ("please enter a and b\n");scanf ("%d %d",&a, &b);if (a>=b) max=a;if (a<=b) max=b;printf ("max=%d\n",max);return 0;
}
[root@chenshuyi c]# ./o
please enter a and b
55 66
max=66
[root@chenshuyi c]# ./o
please enter a and b
77 77
max=77#include <stdio.h>
int main() {int a, b, max;printf ("please enter a and b\n");scanf ("%d %d",&a, &b);if (a!=b);if (a>b) max=a;if (a<b) max=b;printf ("max=%d\n",max);return 0;
}
[root@chenshuyi c]# ./o
please enter a and b
44 44
max=0
[root@chenshuyi c]# ./o
please enter a and b
44 55
max=55

三、逻辑运算符（并且、或者、除非）
PS：优先级从上至下

逻辑非(! NOT）

#include <stdio.h>
int main() {int num = 0;printf ("Please enter num value: ");scanf("%d", &num);if (num != 69) {printf ("num %d is not equal to 69.\n", num);}return 0;
}
~
[root@chenshuyi c]# ./o
Please enter num value: 69
[root@chenshuyi c]# ./o
Please enter num value: 1
num 1 is not equal to 69.

逻辑与(&& AND）

#include <stdio.h>
int main() {int a, b, x, y;printf ("please enter a and b,x and y\n");scanf ("a=%d,b=%d,x=%d,y=%d",&a, &b, &x, &y);if (a==b && x==y){printf ("a=b,x=y\n");}elseprintf ("sorry,I donot konw.\n");return 0;
}
[root@chenshuyi c]# ./o
please enter a and b,x and y
a=1,b=2,x=1,y=1
sorry,I donot konw.
[root@chenshuyi c]# ./o
please enter a and b,x and y
a=1,b=1,x=2,y=2
a=b,x=y

逻辑或(|| OR）

[root@chenshuyi c]# vim or.c
#include<stdio.h>
int main(){int a = 1;int b = 0;printf("%d\n",a || (b++));printf("%d\n",b);
}
[root@chenshuyi c]# ./or
1
0#include<stdio.h>
int main(){int a = 0;int b = 0;printf("%d\n",a || (b++));printf("%d\n",b);
}
[root@chenshuyi c]# ./or
0
1#include<stdio.h>
int main(){int a = 0;int b = 0;printf("%d\n",a || (++b));printf("%d\n",b);
}
[root@chenshuyi c]# ./or
1
1

&&和||的区别

#include<stdio.h>
int main(){printf("%d\n",1 && 1);printf("%d\n",0 && 1);printf("%d\n",0 && 0);printf("%d\n",1 || 1);printf("%d\n",0 || 1);printf("%d\n",0 || 0);return 0;
}
[root@chenshuyi c]# ./and
1
0
0
1
1
0

PS：优先级：算术运算符>关系运算符>赋值运算符

四、位运算符

右移(>>）左移(<<）
按位与(&）
按位或(|）
按位异或(^）
取反(~)

五、赋值运算符

等号(=）
扩展赋值运算符
+= 加赋值 (a += 3 等价于 a = a + 3）
-= 减赋值
*= 乘赋值
/= 除赋值
%= 求余赋值
&= 按位与赋值
| = 按位或赋值
^= 按位异或赋值
<<= 左移位赋值（>>= 右移位赋值）
<> 当右操作数又是一个赋值表达式时，形成多重赋值表达式

六、条件运算符
PS：条件运算符优先级高于赋值、逗号运算符，低于其他运算符。

关系表达式？表达式1 ：表达式2（当表达式多了后就先从右算到左）
三目运算符：条件 ? 结果1 : 结果2（条件成立时，返回：号前的结果；不成立就返回后面的结果）

//例子：判断a小于或者大于b，输出最大值max#include <stdio.h>
int main(){int a, b, max;scanf("a=%d,b=%d",&a,&b);max=a>b?a:b;printf("max=%d\n",max);return 0;
}
[root@chenshuyi c]# gcc -o swap swap.c
[root@chenshuyi c]# ./swap
a=2,b=3
max=3//例子：多个表达式#include<stdio.h>
int main(){int a = 300;int b = 50;int c = a>b? 350: a<b? 360:370;printf("%d\n",c);return 0;
}
[root@chenshuyi c]# ./three
350#include<stdio.h>
int main(){int a = 50;int b = 300;int c = a>b? (b-a): a<b? (a+b):370;printf("%d\n",c);return 0;
}
[root@chenshuyi c]# ./three
350

七、逗号运算符（，）

#include<stdio.h>
int main(){int i = 1;int a = (i+100,i++,i);printf("%d\n",a);return 0;
}
[root@chenshuyi c]# ./comma
2#include<stdio.h>
int main(){int i = 1;int a = (i=i+100,i++,i);printf("%d\n",a);return 0;
}
[root@chenshuyi c]# ./comma
102

八、指针运算符

指针变量(*）
定义：基类型 * 指针变量名；
例子1：通过指针变量访问整型变量

#include <stdio.h>
int main() {int a, b; #定义两个int变量int * pointer_1, * pointer_2; #定义两个指针变量，指向int变量a = 100; b = 10;pointer_1 = &a; #把变量a的地址赋给指针pointer_1pointer_2 = &b;printf ("a = %d, b = %d \n", a, b);printf (" * pointer_1 = %d, * pointer_2 = %d \n", * pointer_1, * pointer_2); #输出的指针变量所指向的整型变量的值return 0;
}~
[root@chenshuyi c]# gcc -o pointer1 pointer1.c
[root@chenshuyi c]# ./pointer1
a = 100, b = 10* pointer_1 = 100, * pointer_2 = 10
[root@chenshuyi c]# vi pointer1.c

例子2：比大小

#include <stdio.h>
int main () {int * p1, * p2, * p, a, b;scanf ("%d, %d", &a, &b);p1 = &a; p2 = &b;if (a < b) {p = p1; p1 = p2; p2 = p;}printf ("a = %d, b = %d\n", a, b);printf ("max = %d, min = %d\n", * p1, * p2);return 0;
}
r
[root@chenshuyi c]# ./pointer2
4,6
a = 4, b = 6
max = 6, min = 4

例子3：算术

#include <stdio.h>
int main () {int maxsum = 123;double temp = 888.8889922111111;temp  += (float)maxsum;printf ("%7.3f, %d\n", (float)temp, (int)temp);return 0;
}
[root@chenshuyi c]# gcc -o compulsion compulsion.c
[root@chenshuyi c]# ./compulsion
1011.889, 1011

九、求字节数运算符（sizeof）

当sizeof(与数据类型（如int，float，char …等）一起使用时，返回分配给该数据类型的内存量。

#include<stdio.h>
int main()
{printf("%d\n",sizeof(char));printf("%d\n",sizeof(int));printf("%d\n",sizeof(float));printf("%d\n", sizeof(double));return 0;
}

当sizeof和表达式一起使用的时候，返回表达式的大小。

#include<stdio.h>
int main() {int a = 1, b = 3;printf ("%d\n", sizeof ( a + b ));return 0;}[root@chenshuyi c]# gcc -o sizeof1 sizeof1.c
[root@chenshuyi c]# ./sizeof1
4

十、强制类型转换运算符

例1：小数转整数

#include <stdio.h>
int main () {float f = 8.88;int i;i = (int) f;printf ("f = %f, i = %d \n", f, i);return 0;
}[root@chenshuyi c]# gcc -o compulsion compulsion.c
[root@chenshuyi c]# ./compulsion
f = 8.880000, i = 8

例2：整数转小数

#include <stdio.h>
int main () {int maxsum = 123;printf ("%lf\n", (double) maxsum);return 0;
}[root@chenshuyi c]# gcc -o compulsion compulsion.c
[root@chenshuyi c]# ./compulsion
123.000000