Function Pointers - Array

#include <stdio.h>

double sum(double num1, double num2){
    return num1 + num2;
}

double sub(double num1, double num2){
    return num1 - num2;
}

double mult(double num1, double num2){
    return num1 * num2;
}

double div(double num1, double num2){
    return num1 / num2;
}

int main(){
    double (*fp[4])(double,double) = { sum, sub, mult, div};
    int op;
    scanf("%d", &op);
    printf("%.2lf\n", fp[op](10, 20));
    return 0;
}