JSFiddle - React, Tailwind, and code Playground

JavaScript

var counter = 0;

function sqrt(x){
    var a, b;
    
    a = 1;
    b = x;
    while (Math.abs(a - b) > 0.1){
        a = (a + b) / 2;
        b = x / a;
        counter++;
    }
    
    return a;
}

var x = 64;
var result = sqrt(x);

alert('Result = ' + result + ' (number of iterations ' + counter + ')');