Simple Calculator
Here we build a simple calculator program which have Basic Mathematical operation like Addition,Subtraction,Multiplication and Division depending upon the input from the user.
To build this program you should hav the prior knowledge of
following Python programming topics:
The source code of the progrma
Python
Javascript
Python
# This function will add the two numbers given to it
def add(a, b):
return a + b
# This function will subtract the two numbers given to it
def subtract(a, b):
return a – b
# This function will multiply the two numbers given to it
def multiply(a, b):
return a * b
# This function divides two numbers
def divide(a, b):
return a / b
# Showing the options to the user
print(“Welcome to a calculator simulation using Python.”)
print(“We have the following options in this program: “)
print(“1.Add \n2.Subtract \n3.Multiply \n4.Divide”)
while True:
# We will now take the input from the user
choice = input(“Please enter the number in accordance with your choice: “)
# We will check if the choice given by the user is a valid option
if choice in (‘1’, ‘2’, ‘3’, ‘4’):
num1 = float(input(“Enter first number: “))
num2 = float(input(“Enter second number: “))
# Based on the choice of the user, we will call the corresponding function
if choice == ‘1’:
print(num1, “+”, num2, “=”, add(num1, num2))
elif choice == ‘2’:
print(num1, “-“, num2, “=”, subtract(num1, num2))
elif choice == ‘3’:
print(num1, “*”, num2, “=”, multiply(num1, num2))
elif choice == ‘4’:
print(num1, “/”, num2, “=”, divide(num1, num2))
# We will now see if the user wants to do more numerical calculations using this program
more_calculations = input(“Let’s do next calculation? (yes/no): “)
if more_calculations == “no” or more_calculations == “No” or more_calculations == “NO”:
break
# This is the scenario where the user inputs a wrong choice
else:
print(“Invalid Input. Please try again!”)
Javascript
function add(a,b)
{
return ((+a)+(+b));
}
// This function will subtract the two numbers given to it
function subtract(a,b)
{
return ((+a)-(+b));
}
// This function will multiply the two numbers given to it
function multiply(a,b)
{
return ((+a)*(+b));
}
// This function divides two numbers
function divide(a,b)
{
return ((+a)/(+b));
}
// Showing the options to the user
window.alert(“Welcome to a calculator simulation using Javascript”);
window.alert(“We have the following options in this program:”);
window.alert(“1.Add \n 2.Subtract \n 3.Multiply \n 4.Divide”);
var isquit = true;
while(isquit)
{
// We will now take the input from the user
var choice = window.prompt(“Please enter the number in accordance with your choice:”);
// We will check if the choice given by the user is a valid option
// Based on the choice of the user, we will call the corresponding function
if (choice == 1)
{
var num1= window.prompt(“Enter first number:”);
var num2= window.prompt(“Enter second number:”);
window.alert(num1 + “+” + num2 + “=” + add(num1,num2));
// We will now see if the user wants to do more numerical calculations using this program
var morecalculations = window.prompt(“Let’s do next calculation? (yes/no)”);
if (morecalculations == “no” || morecalculations == “No” || morecalculations == “nO” || morecalculations == “NO”)
{
isquit= false;
}
}
else if (choice == 2)
{
var num1= window.prompt(“Enter first number:”);
var num2= window.prompt(“Enter second number:”);
window.alert(num1 + “-” + num2 + “=” + subtract(num1,num2));
var morecalculations = window.prompt(“Let’s do next calculation? (yes/no)”);
if (morecalculations == “no” || morecalculations == “No” || morecalculations == “nO” || morecalculations == “NO”)
{
isquit= false;
}
}
else if (choice == 3)
{
var num1= window.prompt(“Enter first number:”);
var num2= window.prompt(“Enter second number:”);
window.alert(num1 + “*” + num2 + “=” + multiply(num1,num2));
var morecalculations = window.prompt(“Let’s do next calculation? (yes/no)”);
if (morecalculations == “no” || morecalculations == “No” || morecalculations == “nO” || morecalculations == “NO”)
{
isquit= false;
}
}
else if (choice == 4)
{
var num1= window.prompt(“Enter first number:”);
var num2= window.prompt(“Enter second number:”);
window.alert(num1 + “/” + num2 + “=” + divide(num1,num2));
var morecalculations = window.prompt(“Let’s do next calculation? (yes/no)”);
if (morecalculations == “no” || morecalculations == “No” || morecalculations == “nO” || morecalculations == “NO”)
{
isquit= false;
}
}
else
{
// This is the scenario where the user inputs a wrong choice
window.alert(“Invalid Input. Please try again!”);
}
}
Sample output
Welcome to a calculator simulation using Python.
We have the following options in this program:
1.Add
2.Subtract
3.Multiply
4.Divide
Please enter the number in accordance with your choice: 1
Enter first number: 2
Enter second number: 4
2.0 + 4.0 = 6.0
Let’s do next calculation? (yes/no): yes
Please enter the number in accordance with your choice: 2
Enter first number: 4
Enter second number: 2
4.0 – 2.0 = 2.0
Let’s do next calculation? (yes/no): 3
Please enter the number in accordance with your choice: 3
Enter first number: 5
Enter second number: 4
5.0 * 4.0 = 20.0
Let’s do next calculation? (yes/no): n