script.js

// Start working code: 
// N.B. In Javascript, an array is a list of elements may it be string, numbers, Boolean, etc. 
// Concatenation: The word concatenate is just another way of saying "to combine" or "to join together". The CONCATENATE function allows you to combine text from different cells into one cell. Concatination is adding two arrays or more than 2 arrays. Similar to add, array1+ array2, concat () method works similarly in javascript. It appends the array elements at the end of the array to which the user wants to combine. (Source: www.educba.com/javascript-array-concat/)
// The Password Generator utilises the concatenation function within javascript

// User input variables: 
var enter;
var confirmNumber;
var confirmCharacter;
var confirmUppercase;
var confirmLowercase;
// Start with setting Password variable values: 
// Special characters
character = ["!", "#", "$", "%", "&", "'", "(", ")", "*", "+", ",", "-", ".", "/", "\:", "\;", " < ", "=", " > ", " ? ", "@", "[", "\\", "]", " ^ ", "_", "`", "{", "|", "}", "~"];
// Numeric characters
number = [1, 2, 3, 4, 5, 6, 7, 8, 9];
// Alphabetical characters
alpha = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"];
// Space is for the Uppercase conversion
space = [];
// Choices declared outside the if statement so they can be concatenated upon condition
var choices;
// converts letters to uppercase 
var toUpper = function (x) {
    return x.toUpperCase();
};
// creates a variable for uppercase conversion
alpha2 = alpha.map(toUpper);

var get = document.querySelector("#generate");

get.addEventListener("click", function () {
    ps = generatePassword();
    document.getElementById("password").placeholder = ps;
});

// Start function to generate password using string
function generatePassword() {
    // Asks for user input
    enter = parseInt(prompt("What is the length of your password? Choose between 8 and 128"));
    // First if statement for user validation (using logial comparison operators || = or)
    if (!enter) {
        alert("Please input a value");
    } else if (enter < 8 || enter > 128) {
        // Validates user input
        // Start user input prompts
        enter = parseInt(prompt("Please choose a number between 8 and 128 (inclusive)"));

    } else {
        // Continues once user input is validated
        confirmNumber = confirm("Do you want the password to contain numbers?");
        confirmCharacter = confirm("Do you want the password to contain special characters?");
        confirmUppercase = confirm("Do you want the password to contain Uppercase letters?");
        confirmLowercase = confirm("Do you want the password to contain Lowercase letters?");
    };

    // Else if for 4 negative options
    if (!confirmCharacter && !confirmNumber && !confirmUppercase && !confirmLowercase) {
        choices = alert("Please choose a criteria in order to continue");

    }
    // First if statement that uses user input prompts to determine choices
    // Else if for 4 positive options
    else if (confirmCharacter && confirmNumber && confirmUppercase && confirmLowercase) {

        choices = character.concat(number, alpha, alpha2);
    }
    // Else if for 3 positive options
    else if (confirmCharacter && confirmNumber && confirmUppercase) {
        choices = character.concat(number, alpha2);
    }
    else if (confirmCharacter && confirmNumber && confirmLowercase) {
        choices = character.concat(number, alpha);
    }
    else if (confirmCharacter && confirmLowercase && confirmUppercase) {
        choices = character.concat(alpha, alpha2);
    }
    else if (confirmNumber && confirmLowercase && confirmUppercase) {
        choices = number.concat(alpha, alpha2);
    }
    // Else if for 2 positive options 
    else if (confirmCharacter && confirmNumber) {
        choices = character.concat(number);

    } else if (confirmCharacter && confirmLowercase) {
        choices = character.concat(alpha);

    } else if (confirmCharacter && confirmUppercase) {
        choices = character.concat(alpha2);
    }
    else if (confirmLowercase && confirmNumber) {
        choices = alpha.concat(number);

    } else if (confirmLowercase && confirmUppercase) {
        choices = alpha.concat(alpha2);

    } else if (confirmNumber && confirmUppercase) {
        choices = number.concat(alpha2);
    }
    // Else if for 1 positive option
    else if (confirmCharacter) {
        choices = character;
    }
    else if (confirmNumber) {
        choices = number;
    }
    else if (confirmLowercase) {
        choices = alpha;
    }
    // Created space variable to fill uppercase conversion
    else if (confirmUppercase) {
        choices = space.concat(alpha2);
    };

    // password variable is an array placeholder for user generated amount of length
    var password = [];

    // Start random selection variables:
    // Random selection for all variables: 
    for (var i = 0; i < enter; i++) {
        var pickChoices = choices[Math.floor(Math.random() * choices.length)];
        password.push(pickChoices);
    }
    // This joins the password array and converts it to a string
    var ps = password.join("");
    UserInput(ps);
    return ps;
}
// This puts the password value into the textbox
// Changed function input to use textcontent
function UserInput(ps) {
    document.getElementById("password").textContent = ps;

}

var copy = document.querySelector("#copy");
copy.addEventListener("click", function () {
    copyPassword();
});
// This copies the password value to clipboard
// Code example demonstrated in a youtube video: 
// Source: https://youtu.be/9sT03jEwcaw
function copyPassword() {
    document.getElementById("password").select();
    document.execCommand("Copy");
    alert("Password has been copied to clipboard!");
}