How to Replace a Switch-Statement

// The four arithmetic operations ... one of these functions is selected
// at runtime with a swicth 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 -  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;
  }

  cout << "Switch: 2+5=" << color="#000080">// display result
}

// Solution with a function pointer -  is a function pointer and points to
// a function which takes two floats and returns a float. The function pointer
// "specifies" which operation shall be executed.
void Switch_With_Function_Pointer(float a, float b, float (*pt2Func)(float, float))
{
  float result = pt2Func(a, b);    // call using function pointer

  cout << "Switch replaced by function pointer: 2-5=";  // display result
  cout << result << endl;
}


// Execute example code
void Replace_A_Switch()
{
  cout << color="#0000ff">"Executing function 'Replace_A_Switch'" << endl;

  Switch(2, 5, /* '+' specifies function 'Plus' to be executed */ '+');
  Switch_With_Function_Pointer(2, 5, /* pointer to function 'Minus' */ &Minus);
}

Important note: A function pointer always points to a function with a specific signature! Thus all functions, you want to use with the same function pointer, must have the same parameters and return-type!