Untitled

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>随机密码生成器</title>
    <meta name="viewport" content="width=device-width">
</head>

<body>
    <h1>随机密码生成器</h1>
    <p>随机生成的密码必须包含以下种类字符：</p>
    <p>
        <input type="checkbox" id="0" checked>
        <label for="0">小写字母</label>
        <input type="checkbox" id="1" checked>
        <label for="1">大写字母</label>
        <input type="checkbox" id="2" checked>
        <label for="2">数字</label>
        <input type="checkbox" id="3" checked>
        <label for="3">特殊字符</label>
    </p>
    <p>
        密码长度：
        <input id="length" type="number" value="8">
    </p>
    <p>
        <button id="gen">生成</button>
    </p>
    <p>
        <input id="pwd" type="text" value="">
    </p>
    <p>源代码可以右键查看，我不会保存你的密码，放心使用</p>
    <script>
        var lowerCase = 'abcdefghijklmnopqrstuvwxyz';
        var upperCase = lowerCase.toUpperCase();
        var number = '1234567890';
        var sign = '!@#$%^&*()-_';
        var source = [lowerCase.split(''), upperCase.split(''), number.split(''), sign.split('')];
        var random = function (length) {
            return Math.floor(Math.random() * length);
        };

        document.getElementById('gen').addEventListener('click', function () {
            var pwd = '';
            var pwdLength = 8;
            var length = +document.getElementById('length').value;
            if (length > 0) {
                pwdLength = length;
            }

            var checkboxs = document.querySelectorAll('[type=checkbox]');
            for (var i = 0; i < checkboxs.length; i++) {
                if (checkboxs[i].checked) {
                    pwd += source[i][random(source[i].length)];
                }
            }

            if (pwd.length === 0) {
                alert('请至少选择一种字符类型');
                return;
            }
            for (; pwd.length < pwdLength;) {
                var s = random(source.length);
                if (checkboxs[s].checked) {
                    var choose = source[s][random(source[s].length)];
                    if (pwdLength > 40 || pwd.indexOf(choose) === -1) {
                        pwd += choose;
                    }
                }
            }

            var chars = pwd.split('');
            chars.sort(function () {
                return Math.random() - 0.5;
            }).sort(function () {
                return Math.random() - 0.5;
            });
            document.getElementById('pwd').value = chars.join('');
            document.getElementById('pwd').select();

            try {
                var successful = document.execCommand('copy');
                var msg = successful ? 'successful' : 'unsuccessful';
                console.log('Copying text command was ' + msg);
            } catch (err) {
                console.log('Oops, unable to copy');
            }
        });
    </script>
</body>

</html>