How to generate a random password using these requirements? [closed]

Answer 1

To check whether it contains a character from either string, you can use Javascript Regular Expressions. Just match your password candidate to those characters as per the link. You are going to try for four matches. The length of the string, you can check in its length property.

Answer 2

Try

var specialCharacters = "~!@#$%^&*()_+=-|\\}]{[\"':;?/>.<,";
var numbers = "0123456789";
var smallLetters = "abcdefghijklmnopqrstuvwxyz";
var capitalLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

var srcs = [specialCharacters, numbers, smallLetters, capitalLetters];

function getRandomChar(string){
    var pos = Math.floor(Math.random() * string.length);
    return string.charAt(pos);
}

//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/array/shuffle [v1.0]
function shuffle(o){ //v1.0
    for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
    return o;
}
function generate(){
    var len = 8 + Math.floor(Math.random() * 5);

    var array = [];
    array.push(getRandomChar(specialCharacters));
    array.push(getRandomChar(numbers));
    array.push(getRandomChar(smallLetters));
    array.push(getRandomChar(capitalLetters));

    for(var i = 4; i < len; i++){
        var pos = Math.floor(Math.random() * srcs.length);
        array.push(getRandomChar(srcs[pos]));
    }
    return shuffle(array).join('')
}

for(var i = 0; i < 10; i++){
    console.log(generate())
}

Demo: Fiddle

Answer 3

Here is what I came up with.

Just run it in the JavaScript console.

(function() {
    var passwd, classTypes, classCount, len, chars, classIndex, charIndex;
    do {
        passwd = "";
        classTypes = [];
        classCount = 0;
        len = Math.round(Math.random() * 5 + 8);
        chars = ["~!@#$%^&*()_+=-|\\}]{[\"':;?/>.<,", "0123456789",
            "abcdefghijklmnopqrstuvwxyz", "ABCDEFGHIJKLMNOPQRSTUVWXYZ"];
        while (passwd.length < len) {
            classIndex = Math.round(Math.random() * 3);
            classTypes[classIndex] = true;
            charIndex = Math.round(Math.random()
                * (chars[classIndex].length - 1));
            passwd += chars[classIndex].charAt(charIndex);
        }
        console.log(JSON.stringify(classTypes));
        classCount = classTypes.filter(function(value, index, object) {
            return value === true;
        }).length;
        console.log("classCount = " + classCount);
        console.log("passwd.length = " + passwd.length);
    } while (classCount < 4);
    console.log("generated pasword is \n" + passwd + "\n");
    console.log("but see http://xkcd.com/936/ for a better approach to paswords");
})();