Question

Using the code snippet below, complete the missing sections using the comments as a guide

********************************************************************************

#include <stdio.h>
#include <stdlib.h>

// The four arithmetic operations ... one of these functions is selected
// at runtime with a switch or a function pointer
float Plus (float a, float b) { return a+b; }
float Minus (float a, float b) { return a-b; }
float Multiply(float a, float b) { return a*b; }
float Divide (float a, float b) { return a/b; }

// Solution with a switch-statement
// <opCode> specifies which operation to execute
void Switch(float a, float b, char opCode) {
float result;

// execute operation
switch(opCode) {
case '+' : result = Plus (a, b); break;
case '-' : result = Minus (a, b); break;
case '*' : result = Multiply (a, b); break;
case '/' : result = Divide (a, b); break;
}

printf("Switch: 2+5=%.2lf\n", result); // display result
}

// Solution with a function pointer
// <pt2Func> is a function pointer and points to a function that takes two floats and returns a float

// 4. fill in the parameters, 3 of them, the 3rd one should be the function pointer

void Replace_Switch( ) {
float result;

// 5. call the function using the function pointer sent in as the third argument //
result =   

printf("Switch replaced by function pointer: 2+5=");
printf("%.2lf\n", result);
}

int main() {
float result;
// 1. declare a function pointer and assign it to point to the plus function //
  

// 2. call function with function pointer assigning result to the function call and sending 2 and 5 as the arguments //
  
printf("%.2lf\n", result);

// the function using switch and no function pointer //
Switch(2,5, '+');

// 3. call function using the function that replaces switch //
    

return 0;
}

Answer 1

#include <stdio.h>
#include <stdlib.h>

// The four arithmetic operations ... one of these functions is selected
// at runtime with a switch or a function pointer
float Plus(float a, float b) { return a + b; }

float Minus(float a, float b) { return a - b; }

float Multiply(float a, float b) { return a * b; }

float Divide(float a, float b) { return a / b; }


// Solution with a switch-statement
// <opCode> specifies which operation to execute
void Switch(float a, float b, char opCode) {
    float result;

// execute operation
    switch (opCode) {
        case '+' :
            result = Plus(a, b);
            break;
        case '-' :
            result = Minus(a, b);
            break;
        case '*' :
            result = Multiply(a, b);
            break;
        case '/' :
            result = Divide(a, b);
            break;
    }

    printf("Switch: 2+5=%.2lf
", result); // display result
}


// Solution with a function pointer
// <pt2Func> is a function pointer and points to a function that takes two floats and returns a float


// 4. fill in the parameters, 3 of them, the 3rd one should be the function pointer
void Replace_Switch(float a, float b, float (*pt2Func)(float, float)) {
    float result;

// 5. call the function using the function pointer sent in as the third argument //
    result = pt2Func(a, b);

    printf("Switch replaced by function pointer: 2+5=");
    printf("%.2lf
", result);
}


int main() {
    float result;
// 1. declare a function pointer and assign it to point to the plus function //
    float (*pt2Func)(float, float) = &Plus;

// 2. call function with function pointer assigning result to the function call and sending 2 and 5 as the arguments //
    result = pt2Func(2, 5);
    printf("%.2lf
", result);

// the function using switch and no function pointer //
    Switch(2, 5, '+');

// 3. call function using the function that replaces switch //
    Replace_Switch(2, 5, pt2Func);
    return 0;
}