JavaScript, calculate a square root using Math.sqrt()

To calculate the square root of the number in JavaScript, you can use the function Math.sqrt(). You pass in a number, and it returns the square root of this number.

console.log(Math.sqrt(4));     // 2
console.log(Math.sqrt(16));    // 4
console.log(Math.sqrt(64));    // 8
console.log(Math.sqrt(100));   // 10

Square root of zero is 0.

console.log(Math.sqrt(0));     // 0

Square root of one is 1.

console.log(Math.sqrt(1));     // 1

If you try to multiply the number by itself in JavaScript and take the square root, you’ll get the same number you’ve started with.

const x = 1234;
console.log(Math.sqrt(x * x)); // 1234 

In JS, you can’t calculate the square root of negative numbers, thus Math.sqrt returns NaN.

console.log(Math.sqrt(-4));    // NaN
console.log(Math.sqrt(-1));    // NaN

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