C++ Program to Make a Simple Mathematical calculator

In this lesson we will learn a C++ program to make a simple mathematical calculator by using a switch statement. First we define the switch structure and see the syntax of the switch structure of the C/C++ language.

The definition and syntax of switch structure are as follows:
You can copy and make a source file compiler
To understand the example, you must have knowledge about the syntax of the case statement and the basic structure of C++.
This program takes an arithmetic operator (+, -, *, /) and two operands from the user and performs the operation on those two operands depending upon the operator.

# include <iostream.h>
#include <conio.h>
void main()
{
    char op;
    float n1, n2;
    cout << "Enter operator  + or - or * or /: ";
    cin >> op;
    cout << "Enter two operands: ";
    cin >> n1 >> n2;
    switch(op)
    {
        case '+':
            cout << n1+n2;
            break;
        case '-':
            cout << n1-n2;
            break;
        case '*':
            cout << n1*2;
            break;
        case '/':
            cout << n1/n2;
            break;
         case '/':
            cout << n1%n2;
            break;
        default:
            cout << "wrong oprater plz inter +,-,*,/ or %";
            break;
    }
 getch();
}

C program for simple calculator

C++ and c have almost same structure but only some differences

1. In the C++ preprocessing directive iostream. h is used for including standard input/output functions, while in the C language stdio. h is used
2. For output cout is used in C++, while in the C language, printf is used for output
3. In C++, cin is used for getting input from the user, while in C coding, the scanf function is used for getting input from the user.
4. In C++, format specifiers are not used to print output and for getting input, while format specifiers are used in C coding.

# include <stdio.h>
 #include <conio.h>
void main()
{
clrscr();
    char op;
    float n1, n2;
    printf( "Enter operator  + or - or * or /: ");
    scanf("%c",op);
    printf( "Enter two operands: ");
    scanf("%f %f",&n1,&n2);
    switch(op)
    {
        case '+':
            printf("%f", n1+n2);
            break;
        case '-':
            printf("%f", n1-n2);
            break;
        case '*':
            printf("%f", n1*n2);
            break;
        case '/':
             printf("%f", n1/n2);
            break;
         case '%':
             printf("%f", n1%n2);
             break;
        default:
            printf("wrong oprater plz inter +,-,*,/ or %");
            break;
    }
 getch();
}