Modulus of Negative Numbers in C

Here we will see what will be the result if we use negative numbers to get the modulus. Let us see the following programs and their outputs to get the idea.

Example

#include
int main() {
   int a = 7, b = -10, c = 2;
   printf("Result: %d", a % b / c);
}

Output

Result: 3

Here the precedence of % and / are same. So % is working at first, so a % b is generating 7, now after dividing it by c, it is generating 3. Here for a % b, the sign of left operand is appended to the result. Let us see it more clearly.

Example

#include
int main() {
   int a = 7, b = -10;
   printf("Result: %d", a % b);
}

Output

Result: 7

If we interchange the sign of a and b, then it will be like below.

Example

#include
int main() {
   int a = -7, b = 10;
   printf("Result: %d", a % b);
}

Output

Result: -7

Similarly if both are negative, then also the result will be negative.

Example

#include
int main() {
   int a = -7, b = -10;
   printf("Result: %d", a % b);
}

Output

Result: -7