JavaScript: Finding Odd and Even Numbers

Posted by


In JavaScript, you can easily determine whether a number is odd or even using a simple mathematical operation. Here’s a detailed tutorial on how to get odd and even numbers with JavaScript:

Method 1: Using the modulo operator (%)

The modulo operator (%) in JavaScript returns the remainder of a division operation. You can use this operator to check if a number is odd or even as follows:

  1. Create a function to determine if a number is odd or even:
function checkOddEven(num) {
  if (num % 2 === 0) {
    console.log(num + " is even");
  } else {
    console.log(num + " is odd");
  }
}
  1. Call the function with a number to check if it’s odd or even:
checkOddEven(5); // Output: 5 is odd
checkOddEven(10); // Output: 10 is even

Method 2: Using bitwise operator (&)

Another way to determine if a number is odd or even in JavaScript is by using the bitwise AND operator (&). This method is more efficient than using the modulo operator for large numbers. Here’s how you can implement it:

  1. Create a function to check if a number is odd or even using the bitwise operator:
function checkOddEvenBitwise(num) {
  if (num & 1) {
    console.log(num + " is odd");
  } else {
    console.log(num + " is even");
  }
}
  1. Call the function with a number to check if it’s odd or even:
checkOddEvenBitwise(7); // Output: 7 is odd
checkOddEvenBitwise(12); // Output: 12 is even

Method 3: Using a for loop to iterate through a range of numbers

If you want to check multiple numbers at once, you can use a for loop to iterate through a range of numbers and determine if each number is odd or even. Here’s an example:

function checkOddEvenRange(start, end) {
  for (let i = start; i <= end; i++) {
    if (i % 2 === 0) {
      console.log(i + " is even");
    } else {
      console.log(i + " is odd");
    }
  }
}

// Call the function with a range of numbers:
checkOddEvenRange(1, 10);

This will output whether each number in the range from 1 to 10 is odd or even.

In conclusion, these are the three common methods to get odd and even numbers with JavaScript. You can choose the method that best suits your requirements based on efficiency and readability. Happy coding!