Create a Simple calculator in C++

In this tutorial, we will see the basic implementation of a simple calculator in C++. It includes all the basic operations:

1. Addition(+)
2. Subtraction(-)
3. Multiplication(*)
4. Division(/)
5. Modulo(%)

How to write code for a simple calculator in C++

• First, we will take input char ch. It will be the operation we want to perform.
• + for addition
• – for subtraction
• / for division
• * for multiplication
• % for modulo i.e remainder of two numbers
• Then we take input for our first number i.e N1.
• And our second number N2.
• else if it is equal to X or x, it means to end up doing calculations i.e stop the calculator.
• else if it is another char which is unidentified like ‘$’ or ‘#’, it will print invalid operation for it.

 

Important point while writing code:

While performing division, do check that n2 is not equal to zero. In the case, it equals to zero division cant be performed.

Here, is the code:

#include <iostream>
using namespace std;

int main(){
  char ch;
  
   while(true){
    cin>>ch;
    
    if(ch=='+'||ch=='-'||ch=='*'||ch=='/'||ch=='%'){
      int N1,N2;
      cin>>N1;
      cin>>N2;
      
            if(ch=='+'){
        cout<<N1+N2<<endl;
      }
      else if(ch=='-'){
        cout<<N1-N2<<endl;
      }
      else if(ch=='*'){
        cout<<N1*N2<<endl;
      }
      else if(ch=='/'){
        if(N2!=0){
          cout<<(double)N1/N2<<endl;
        }
                else{cout<<"cant divide"<<endl;}
      }
      else{
        if(N2!=0){
          cout<<N1%N2<<endl;
        }
      }
    }
    else if(ch=='X'||ch=='x'){
      break;
    }
    else{
      cout<<"Invalid operation. Try again."<<endl;
    }
  }
  return 0 ;
}

INPUT:

+
5 2
/
94 2
/ 
5 0
$ 
x

Output:

Try it on your machine. That will be more fun!

This is a basic code using the if-else loop to write a program of a simple calculator in c++ by taking inputs from keyboards. The code could also be written using switch cases.

Also, refer to:

Using vector class without header file in C++