function with switch in C++ program

Here on this page, we will discuss function with switch statement in C++,

As we know we used Function to reduce program size in C++ see this Program creating a menu using switch Statement

In the below program, we call a function in every case statement to reducing code size of a Program.

In the program below, we have used three user-defined functions.

<preint get_sum();
int get_sub();
int get_mul();

In the program below, each case statement will perform a different task.

Here is the program below,

Example of function with switch statement in C++

#include<iostream>
#include<stdlib>  // exit(0)
using namespace std;

int num1, num2, result;  // global variable declaration

 int get_sum();
 int get_sub();
 int get_mul();

  int get_sum()
    {
       cout<<"Enter any two number: ";
       cin>>num1>>num2;

       result = num1 + num2;
       return result;
    }
   int get_sub()
    {
       cout<<"Enter any two number: ";
       cin>>num1>>num2;

       result = num1 - num2;
       return result;
    }
   int get_mul()
    {
       cout<<"Enter any two number: ";
       cin>>num1>>num2;

       result = num1 * num2;
       return result;
    }
 int main()
  {
    int select;
    cout<<"1.Addition\n";
    cout<<"2.Subtraction\n";
    cout<<"3.Multiply\n";
    cout<<"0.Exit";

    cout<<"\nEnter Your Choice: ";
    cin>>select;
    cout<<endl;

 switch(select)
  {
    case 1:
            get_sum();
            cout<<"\nTotal: "<<result;
            break;

    case 2:
            get_sub();
            cout<<"\nSubtraction: "<<result;
            break;

    case 3:
            get_mul();
            cout<<"\nMultiply: "<<result;
            break;

    case 0: exit(0);

    default:
             cout<<"\ninvalid choice....";
  }

return 0;
}

OUTPUT

1.Addition 
2.Subtraction 
3.Multiply 
0.Exit 

Enter Your choice: 1 

Enter First Number: 5 
Enter Second Number: 8 

Total: 13

 

a good code always has fewer statements, so here is another one,

#include<iostream>
#include<stdlib>  // exit(0)
using namespace std;

 int get_num1();
 int get_num2();

 int result;

  int get_num1()
    {
       int num1;
       cout<<"\nEnter First Number: "; cin>>num1;

       return num1;
    }

  int get_num2()
    {
       int num2;
       cout<<"\nEnter Second Number: "; cin>>num2;

       return num2;
    }


 int main()
  {
  
    int choice;
    cout<<"1.Addition\n";
    cout<<"2.Subtraction\n";
    cout<<"3.Multiply\n";
    cout<<"0.Exit";

    cout<<"\nEnter Your Choice: "; cin>>choice;

 switch(choice)
  {
  case 1:

	 result = get_num1()+get_num2();
	 cout<<"\nTotal: "<<result;
	 break;

  case 2:
	 result = get_num1()-get_num2();
	 cout<<"\nSubtraction: "<<result;
	 break;

  case 3:
	 result = get_num1()*get_num2();
	 cout<<"\nMultiply: "<<result;
	 break;

  case 0:
	 exit(0);

  default:
	  cout<<"\ninvalid choice....";
 }

return 0;
}

OUTPUT

1.Addition 
2.Subtraction 
3.Multiply 
0.Exit 

Enter Your choice: 2 
Enter First Number: 5 

Enter Second Number: 8 

Substrection: -3

Explanation

• In the program, we have declared two variables but both variables are declared inside different functions. i.e. variable num1 inside function get_num1() while variable num2 inside function get_num2()

• Both functions are called from each case statement. Which will be executed if the condition in the case statement will be true.
  suppose user-entered first number 5 and second 8 and select option 2 so,
• In the switch statement case 2 , the condition is becoming true so it will be executed.

---

C++ Examples