How to Represent Infinity in C Language

In C language, you can use the predefined constant INFINITY to represent positive infinity. This constant is defined in the header file <math.h>, and its usage is as follows:

#include <stdio.h>
#include <math.h>

int main() {

    double x = 1.0 / 0.0;  // positive infinity
    double y = -1.0 / 0.0;  // negative infinity

    if (x == INFINITY) {
        printf("x is infinity\n");
    }
    if( y == -INFINITY) {
        printf("y is negative infinity\n");
    }

    return 0;
}

In the above code, the INFINITY constant represents positive infinity, and the -INFINITY constant represents negative infinity.

For floating-point division, if the divisor is 0.0, the result can be positive infinity (positive number divided by 0.0), negative infinity (negative number divided by 0.0), or NaN (0.0 divided by 0.0), rather than an error or exception.