Python Programs to Check if a Number is Odd or Even

One of the most fundamental concepts in programming involves determining whether a number is even or odd. In this article, we’ll walk you through how to write a simple Python program to achieve this. This is a great starting point for understanding basic arithmetic operations and conditional logic in Python.

• An Even Number is an integer that is divisible by 2 without leaving a remainder. For Example: 0, 2, 4, 6, 8, 10, etc.
• An Odd Number is an integer that is not divisible by 2, leaving a remainder of 1. For Example: 1, 3, 5, 7, 9, etc.

This article discusses the most common methods, each with an explanation and example.

1. Using the Modulo Operator (%)

Using the modulo operator is a straightforward method for checking whether a number is even or odd in Python. The modulo operator (%) in Python is used to compute the remainder of the division between two numbers. When a number is divided by 2, the remainder is 0, so it’s an even number; otherwise, it is odd.

Steps:

1. Get Input:
   • Use input() function to get the number that you want to check.
2. Use the Modulo Operator:
   • Divide the number by 2 and find the remainder using the modulo operator (%).
   • The modulo operator returns the remainder of a division.
3. Check the Remainder:
   • If the remainder is 0, the number is even.
   • If the remainder is 1, the number is odd.
4. Output the Result:
   • Print or return a message indicating whether the number is even or odd.

Code Example

number = int(input("Enter a number: "))

# Check if the number is even or odd using the modulo operator
if number % 2 == 0:
    print(f"{number} is even.")
else:
    print(f"{number} is odd.")Code language: Python (python)

2. Using Integer Division operator (//)

Integer Division operator (//) divides two numbers and returns the quotient by discarding the decimal part (i.e., the result is always an integer or a whole number if both inputs are integers).

For Example, (10 // 3) Output: 3 (10 ÷ 3 = 3.33; decimal part discarded).

This method uses integer division to determine whether a number is even or odd. The result of integer division is multiplied by 2 and compared with the original number.

Example

• For number = 4: (number // 2) * 2 = (4 // 2) * 2 = 4. Since 4 equals the original number, it is even.
• For number = 5: (number // 2) * 2 = (5 // 2) * 2 = 4. Since 4 does not equal the original number, it is odd.

Code Example

number = int(input("Enter a number: "))

# Check if the number is even or odd using integer division
if (number // 2) * 2 == number:
    print(f"{number} is even.")
else:
    print(f"{number} is odd.")Code language: Python (python)

Explanation

• Input: The program takes an integer input from the user.
• Integer division (//): The expression number // 2 performs integer division, discarding any remainder.
• Multiplication and comparison: The result of number // 2 is multiplied by 2. If the result equals the original number, it is even; otherwise, it is odd.
• Output: The program prints whether the number is even or odd.