strong password generator javascript code example

Example 1: javascript password generator example

function generatePassword(passwordLength) {
  var numberChars = "0123456789";
  var upperChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  var lowerChars = "abcdefghijklmnopqrstuvwxyz";
  var allChars = numberChars + upperChars + lowerChars;
  var randPasswordArray = Array(passwordLength);
  randPasswordArray[0] = numberChars;
  randPasswordArray[1] = upperChars;
  randPasswordArray[2] = lowerChars;
  randPasswordArray = randPasswordArray.fill(allChars, 3);
  return shuffleArray(randPasswordArray.map(function(x) { return x[Math.floor(Math.random() * x.length)] })).join('');
}

function shuffleArray(array) {
  for (var i = array.length - 1; i > 0; i--) {
    var j = Math.floor(Math.random() * (i + 1));
    var temp = array[i];
    array[i] = array[j];
    array[j] = temp;
  }
  return array;
}

alert(generatePassword(12));

Example 2: JavaScript Password Generator

/*
    This code comes from Vincent Lab
    And it has a video version linked here: https://www.youtube.com/watch?v=PtnYuiIyqeM
*/

function generate() {

    let password = "";

    let length = +document.getElementById("length").value;

    let lowerCase = document.getElementById("lowercase").checked;
    let upperCase = document.getElementById("uppercase").checked;
    let symbol = document.getElementById("symbols").checked;
    let number = document.getElementById("numbers").checked;

    if (lowerCase + upperCase + symbol + number <= 0)
        return;

    for (let i = 0; i < length; i++) {

        const r = generater(0, 3);
        if (lowerCase && r === 0) {
            password += generateRandomLowerCase();
        } else if (upperCase && r === 1) {
            password += generateRandomUpperCase();
        } else if (symbol && r === 2) {
            password += generateRandomSymbol();
        } else if (number && r === 3) {
            password += generater(0, 9);
        } else {
            i--;
        }

    }

    document.getElementById("result").textContent = password;

}

generate();

function generateRandomLowerCase() {
    return String.fromCharCode(generater(97, 122));
}

function generateRandomUpperCase() {
    return String.fromCharCode(generater(65, 90));
}

function generateRandomSymbol() {
    const symbols = "~*$%@#^&!?*'-=/,.{}()[]<>";
    return symbols[generater(0, symbols.length - 1)];
}

function generater(min = 0, max = 1) {
    return Math.floor(Math.random() * (max + 1 - min) + min);
}