Difference between %f and %lf

Question

#include <stdio.h>

int main() {

double a,b,c;
scanf("%f %f",&a,&b);

c=b/0.02;

if(c<a){
printf("Dollars");

}else{
printf("Pesos");

}
return 0;
}
/* when using “%lf” it works ,so what’s the difference between “%f” and “%lf” */

Answer 1

For printf, arguments of type float are promoted to double so both %f and %lf are used for double. For scanf, you should use %f for float and %lf for double.