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In this C++ program tutorial, we will write a code on how to make a simple calculator using switch statement in C++ or in other words create a simple calculator to add, subtract, multiply and divide using switch and break statement.

In order to understand the program you need to know about the following topics in C++:

• C++ switch Statement
• C++ break Statement
• C++ operator

C++ Program to Make a Simple Calculator Using Switch Case Statement

# include <iostream>
using namespace std;

int main() 
{
    char op;
    float num1, num2;

    cout << "Choose the operator to perform: +, -, *, / : ";
    cin >> op;

    cout << "\nEnter the First Number: ";
    cin >> num1;
    cout << "Enter the Second Number: ";
    cin >> num2;

    switch(op) 
    {
        case '+':
            cout << num1 << " + " << num2 << " = " << num1 + num2;
            break;

        case '-':
            cout << num1 << " - " << num2 << " = " << num1 - num2;
            break;

        case '*':
            cout << num1 << " * " << num2 << " = " << num1 * num2;
            break;

        case '/':
            cout << num1 << " / " << num2 << " = " << num1 / num2;
            break;

        default:
            // If chose other than the given options
            cout << "Error! Operation not supported";
            break;
    }

    return 0;
}

Output:

Choose the operator to perform: +, -, *, / : +
Enter the First Number: 20
Enter the Second Number: 30
20 + 30 = 50

Choose the operator to perform: +, -, *, / : *
Enter the First Number: 5
Enter the Second Number: 12
5 * 12 = 60

Choose the operator to perform: +, -, *, / : &
Enter the First Number: 12
Enter the Second Number: 52
Error! Operation not supported

In this tutorial, you will learn to write a code on how to calculate the average percentage marks in C++. You may go through the following topics in C++:

• C++ operator
• C++ loop

We will do calculate the total marks, average, and then the percentage of the subjects entered by the user. The program also takes the user input for the marks obtained in the subjects.

How to find the average and Percentage of marks?

Total Marks = Sum of the marks of all subjects
Average Marks = Total Marks/No. of subjects
Percentage = ((marks obtained)/(total marks) *100)

C++ Program to find Total, Average and Percentage Marks

#include <iostream>
using namespace std;

int main()
{
  int sub, i;
  float marks, total = 0.0 f, avg, perc;

  cout << "Enter the number of subjects: ";
  cin >> sub;

  cout << "Enter marks on each subject:\n";
  for (i = 0; i < sub; i++)
  {
    cin >> marks;
    total += marks;
  }

  // Average Calculation
  avg = total / sub;

  // Each marks is out of 100
  perc = (total / (sub *100)) *100;

  cout << "Total Marks Obtained: " << total;
  cout << "\nAverage Marks: " << avg;
  cout << "\nPercentage: " << perc;

  return 0;
}

Output:

Enter the number of subjects: 5
Enter marks on each subject:
84
67
62
80
76
Total Marks Obtained: 369
Average Marks: 73.8
Percentage: 73.8

Here, the total marks are taken as 100 on each subject, you may take the total marks from the users too.

In this tutorial, we will write a C++ program to find the sum and product of all elements of an array. You may go through the following topics in C++ used in the program below.

• C++ operator
• C++ loop

Explanation: The program takes input for the size of an array and the elements of an array. Then the array is iterated using for loop and the sum and the product of an element are calculated. Lastly, the result is displayed.

However, the program solves two separate questions at a time:

• C++ program to calculate the sum of all elements in an array
• C++ program to calculate the product of all elements in an array

C++ Program to Calculate Product and Sum of all Elements in an Array

Source code:

#include<iostream>
using namespace std;

int main ()
{
    int arr[10], size, i, sum = 0, product = 1;
    
    //user input
    cout << "Enter the size of an array: ";
    cin >> size;
    
    cout << "Enter " << size << " elements in an array: " << endl;
    for (i = 0; i < size; i++)
        cin >> arr[i];
    
    //calculation
    for (i = 0; i < size; i++)
    {
        sum += arr[i];
        product *= arr[i];
    }
    
    //Display
    cout << "\nSum of array elements: " << sum;
    cout << "\nProduct of array elements: " << product;
    return 0;
}

Output:

Enter the size of an array: 5
Enter 5 elements in an array:
2
3
4
5
6
Sum of array elements: 20
Product of array elements: 720