C / C++中的模运算符(％)及其示例

用％表示的模运算符是算术运算运算符。
模除法运算符产生整数除法的余数。

语法：如果x和y是整数，则表达式：

x % y

当x除以y时，产生余数。

返回值：

• 如果y将x完全除，则表达式的结果为0。
• 如果x不能被y整除，则结果将是[1，x-1]范围内的余数。
• 如果x为0，则被零除是编译时错误。

例如：考虑以下代码：

C++

// Program to illustrate the
// working of modulo operator
#include 
using namespace std;
 
int main(void)
{
 
    // To store two integer values
    int x, y;
 
    // To store the result of
    // the modulo expression
    int result;
 
    x = 3;
    y = 4;
    result = x % y;
    cout << result << endl;
 
    result = y % x;
    cout << result << endl;
 
    x = 4;
    y = 2;
    result = x % y;
    cout<

---

C

// Program to illustrate the
// working of modulo operator
 
#include 
 
int main(void)
{
 
    // To store two integer values
    int x, y;
 
    // To store the result of
    // the modulo expression
    int result;
 
    x = 3;
    y = 4;
    result = x % y;
    printf("%d", result);
 
    result = y % x;
    printf("\n%d", result);
 
    x = 4;
    y = 2;
    result = x % y;
    printf("\n%d", result);
 
    return 0;
}

输出

3
1
0

模运算符的限制：
模运算符有很多限制。

1. ％运算符不能应用于浮点数，即浮点数或双精度数。如果您尝试将模运算符与浮点常量或变量一起使用，则编译器将产生错误：

C++

// Program to illustrate the
// working of modulo operator
#include 
using namespace std;
 
int main()
{
     
    // To store two integer values
    float x, y;
 
    // To store the result of
    // the modulo expression
    float result;
 
    x = 2.3;
    y = 1.5;
    result = x % y;
    cout << result;
 
    return 0;
}
 
// This code is contributed by Harshit Srivastava

C

// Program to illustrate the
// working of modulo operator
 
#include 
 
int main(void)
{
 
    // To store two integer values
    float x, y;
 
    // To store the result of
    // the modulo expression
    float result;
 
    x = 2.3;
    y = 1.5;
    result = x % y;
    printf("%f", result);
 
    return 0;
}

编译错误：

Compilation Error in C code :- prog.c: In function 'main':
prog.c:19:16: error:
 invalid operands to binary % (have 'float' and 'float')
     result = x % y;
                ^           

模运算符的结果符号与机器有关的负操作数有关，因为该操作是下溢或上溢的结果。

C++

// Program to illustrate the
// working of the modulo operator
#include 
using namespace std;
 
int main(void)
{
     
    // To store two integer values
    int x, y;
 
    // To store the result of
    // the modulo expression
    int result;
 
    x = -3;
    y = 4;
    result = x % y;
    cout << result << endl;
 
    x = 4;
    y = -2;
    result = x % y;
    cout << result << endl;
 
    x = -3;
    y = -4;
    result = x % y;
    cout << result;
 
    return 0;
}
 
// This code is contributed by Harshit Srivastava

C

// Program to illustrate the
// working of the modulo operator
 
#include 
 
int main(void)
{
 
    // To store two integer values
    int x, y;
 
    // To store the result of
    // the modulo expression
    int result;
 
    x = -3;
    y = 4;
    result = x % y;
    printf("%d", result);
 
    x = 4;
    y = -2;
    result = x % y;
    printf("\n%d", result);
 
    x = -3;
    y = -4;
    result = x % y;
    printf("\n%d", result);
 
    return 0;
}

输出

-3
0
-3

注意：一些编译器可能会将表达式的结果显示为1，而另一些可能会显示-1。这取决于编译器。