# error directive in c


Syntax : #error
If compiler compiles this line then it shows a compiler fatal error i.e it only issue an error message and this error message includes . i.e it only issue an error message and this error message includes .
Example :

#include<stdio.h>
#ifndef __MATH_H
#error First include then compile
#else
int main(){
    float a,b=25;
    a=sqrt(b);
    printf("%f",a);
    return 0;
}
#endif
Output: compiler error --> Error directive :First include then compile







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