$.rand()

Echos a random string.
$.rand = function (length = 8, nosymbols = true, nonumbers = false) {
    var symbols = "!#$%&()*+,-.:;<=>?@_";
    var numbers = "0123456789";
    var characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    if (nosymbols) {
        characters += numbers;
    } else {
        characters += numbers + symbols;
    }

    if (nonumbers) {
        characters = characters.replace(numbers, "");
    }

    var random_string = '';
    for (var i = 0; i < length; i++) {
        var char_index = 0;
        if (i == 0) {
            char_index = Math.floor(Math.random() * (characters.length - symbols.length));
        } else if (i == length - 1) {
            char_index = Math.floor(Math.random() * (characters.length - symbols.length - 1));
        } else {
            char_index = Math.floor(Math.random() * characters.length);
        }
        random_string += characters.charAt(char_index);
    }
    return random_string;
};