Check for perfect square in JavaScript

We are required to write a JavaScript function that takes in a number and returns a boolean based on the fact whether or not the number is a perfect square.

A perfect square is a number that can be expressed as the product of an integer with itself. For example, 16 is a perfect square because 4 × 4 = 16.

Examples of Perfect Square Numbers

144 (12²), 196 (14²), 121 (11²), 81 (9²), 484 (22²)

Method 1: Using Math.sqrt()

The most straightforward approach is to find the square root and check if it's an integer:

const isPerfectSquare = (num) => {
    if (num 

true
false
true
true


Method 2: Using Loop Iteration

This approach iterates through numbers until we find a match or exceed the target:

const isPerfectSquareLoop = (num) => {
    if (num 

true
false
true


Method 3: Using Binary Search

For better performance with large numbers, binary search can be used:

const isPerfectSquareBinary = (num) => {
    if (num 

true
false


Comparison

Conclusion

The Math.sqrt() method is the most efficient and readable approach for checking perfect squares. Use loop-based methods when you need to understand the underlying logic or avoid built-in math functions.