The main problem related to That executes after page load is that it can slow down the loading of a web page.

window.onload = function() { //code goes here };

This code is saying that when the window loads, the function will run.

## Math

There are a few ways to do math in JavaScript. The most common way is to use the Math object. You can use the Math.random() function to get a random number between 0 and 1 . You can also use the Math.floor() and Math.ceil() functions to round off numbers or return them to their nearest integer value.

You can also use the Math.max() and Math.min() functions to find the maximum or minimum value of a number, respectively. Finally, you can use the Math.pow() function to calculate mathematical operations like exponentiation or square roots.

## Swap

Swap is a utility function in JavaScript that allows you to exchange values between two variables.

The syntax for Swap is as follows:

var firstValue = secondValue;

firstValue = secondValue; // This will swap the values of firstValue and secondValue.