Programs to create a simple calulator have been shown here. In this calculator, the user can do addition, subtraction, multiplication, division and power operations.

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1. Program & output

## 1. Programs to create simple calculator

The following section covers the C, C++, Java, Python and C# programs to make a simple calculator. The user provides an arithmetic expression as the input, and it is evaluated to produce the output. The input expression consists of two operands and one operator (addition, multiplication, subtraction, division and power). The syntax of the input expression is <First operand> <Operator> <Second operand>.

## 1.1. C Program to create simple calculator

Code has been copied
/*******************************
alphabetacoder.com
C program for simple calculator
********************************/

#include <stdio.h>
#include <math.h>

int main() {
// declare variables
double f, l;
char op;

// take input
// input consist of three terms
// two operands and one operator
printf("Allowed opeators: (+, -, *, /, ^)\n");
printf("Enter the expression  (operand1 operator operand2): ");
scanf("%lf %c %lf", & f, & op, & l);

// calculate value according to
// the operator in input expression
switch (op) {
case '+':
printf("%lf + %1lf = %lf", f, l, f + l);
break;
// for subtraction
case '-':
printf("%lf - %1lf = %lf", f, l, f - l);
break;
// for multiplication
case '*':
printf("%lf * %1lf = %lf", f, l, f * l);
break;
// for division
case '/':
printf("%lf / %1lf = %lf", f, l, f / l);
break;
// for power
case '^':
printf("%lf ^ %1lf = %lf", f, l, pow(f, l));
break;
// for wrong operator
default:
printf("Input operator is not correct!");
}

return 0;
}


Output

#### Case 1:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 3.5 + 4.65

3.500000 + 4.650000 = 8.150000

#### Case 2:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 8.5 * 5

8.500000 * 5.000000 = 42.500000

#### Case 3:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 10 * 3.2

10.000000 ^ 3.200000 = 1584.893192

## 1.2. C++ Program to create simple calculator

Code has been copied
/********************************
alphabetacoder.com
C++ program for simple calculator
*********************************/

#include <iostream>
#include <cmath>

using namespace std;

int main() {
// declare variables
double f, l;
char op;

// take input
// input consist of three terms
// two operands and one operator
cout << "Allowed opeators: (+, -, *, /, ^)\n";
cout << "Enter the expression  (operand1 operator operand2): ";
cin >> f;
cin >> op;
cin >> l;

// calculate value according to
// the operator in input expression
switch (op) {
case '+':
cout << f <<" + " << l <<" = " << f + l;
break;
// for subtraction
case '-':
cout << f <<" - " << l <<" = " << f - l;
break;
// for multiplication
case '*':
cout << f <<" * " << l <<" = " << f * l;
break;
// for division
case '/':
cout << f <<" / " << l <<" = " << f / l;
break;
// for power
case '^':
cout << f <<" ^ " << l <<" = " << pow(f, l);
break;
// for wrong operator
default:
printf("Input operator is not correct!");
}

return 0;
}


Output

#### Case 1:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 3.5 + 6.2

3.5 + 6.2 = 9.7

#### Case 2:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 345 * 21.5

345.000000 * 21.500000 = 7417.500000

#### Case 3:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 100 / 33.33

100.000000 / 33.330000 = 3.000300

## 1.3. Java Program to create simple calculator

Code has been copied
/*********************************
alphabetacoder.com
Java program for simple calculator
**********************************/

import java.util.Scanner;

public class Main {

public static void main(String[] args) {
// declare variables
double f, l;
char op;

// declare instance of Scanner class
Scanner sc = new Scanner(System.in);

// take input
System.out.println("Allowed opeators: (+, -, *, /, ^)");
System.out.print("Enter the expression  (operand1 operator operand2): ");
f = sc.nextDouble();
op = sc.next().charAt(0);
l = sc.nextDouble();

// calculate value according to
// the operator in input expression
// round off to 4 decimal places
switch (op) {
case '+':
System.out.println(f + " + " + l + " = " + (double) Math.round((f + l) * 10000) / 10000);
break;
// for subtraction
case '-':
System.out.println(f + " - " + l + " = " + (double) Math.round((f - l) * 10000) / 10000);
break;
// for multiplication
case '*':
System.out.println(f + " * " + l + " = " + (double) Math.round((f * l) * 10000) / 10000);
break;
// for division
case '/':
System.out.println(f + " / " + l + " = " + (double) Math.round((f / l) * 10000) / 10000);
break;
// for power
case '^':
System.out.println(f + " ^ " + l + " = " + (double) Math.round((Math.pow(f, l)) * 10000) / 10000);
break;
// for wrong operator
default:
System.out.println("Input operator is not correct!");
}
}
}


Output

#### Case 1:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 4.5 ^ 2

4.5 ^ 2.0 = 20.25

#### Case 2:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 4.71 + 8.34

4.71 + 8.34 = 13.05

#### Case 3:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 49 / 41

49.0 / 41.0 = 1.1951

## 1.4. Python Program to create simple calculator

Code has been copied
#************************************
#       alphabetacoder.com
#Python program for simple calculator
#************************************/

# take input
# input consist of three terms
# two operands and one operator
print("Allowed opeators: (+, -, *, /, ^)")
[f, op, l] = input("Enter the expression  (operand1 operator operand2): ").split()

# convert to float
f = float(f)
l = float(l)

# calculate value according to
# the operator in the input expression
# round to 4 decimal places
if op == '+':
print(f, "+",l ,"=", round(f + l, 4))
# for subtraction
elif op == '-':
print(f, "-",l ,"=", round(f - l, 4))
# for multiplication
elif op == '*':
print(f, "*",l ,"=", round(f * l, 4))
# for division
elif op == '/':
print(f, "/",l ,"=", round(f / l, 4))
# for power
elif op == '^':
print(f, "^",l ,"=", round(f ** l, 4))
# for wrong operator
else:
print("Input operator is not correct!")


Output

#### Case 1:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 7.9 ^ 4.8

7.9 ^ 4.8 = 20352.138

#### Case 2:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 45 - 25.75

45.0 - 25.75 = 19.25

#### Case 3:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 7 / 9

7.0 / 9.0 = 0.7778

## 1.5. C# Program to create simple calculator

Code has been copied
/*******************************
alphabetacoder.com
C# program for simple calculator
********************************/

using System;

namespace Calculator {
class Program {
static void Main(string[] args) {
// declare variables
double f, l;
char op;
string[] input;

// take input in single line
// input consist of three terms
// two operands and one operator
Console.WriteLine("Allowed opeators: (+, -, *, /, ^)");
Console.Write("Enter the expression  (operand1 operator operand2): ");

// fetch the value of two operands and one operator
f = double.Parse(input);
op = char.Parse(input);
l = double.Parse(input);

// calculate value according to
// the operator in input expression
// Round off to 4 decimal places
switch (op) {
case '+':
Console.WriteLine(f + " + " + l + " = " + Math.Round((f + l), 4));
break;
// for subtraction
case '-':
Console.WriteLine(f + " - " + l + " = " + Math.Round((f - l), 4));
break;
// for multiplication
case '*':
Console.WriteLine(f + " * " + l + " = " + Math.Round((f * l), 4));
break;
// for division
case '/':
Console.WriteLine(f + " / " + l + " = " + Math.Round((f / l), 4));
break;
// for power
case '^':
Console.WriteLine(f + " ^ " + l + " = " + Math.Round(Math.Pow(f, l), 4));
break;
// for wrong operator
default:
Console.WriteLine("Input operator is not correct!");
break;
}

// wait for user to press any key
}
}
}


Output

#### Case 1:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 654 / 56

654 / 56 = 11.6786

#### Case 2:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 34 ^ 2.25

34 ^ 2.25 = 2791.4353

#### Case 3:

Allowed opeators: (+, -, *, /, ^)

Enter the expression (operand1 operator operand2): 33 + 45.345

33 + 45.345 = 78.345