jquery注册验证实例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>注册验证</title>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
    <style>
        .error {
            color: red;
        }
    </style>
</head>
<body>
    <form id="registerForm">
        <label for="username">用户名:</label>
        <input type="text" id="username" name="username">
        <span class="error" id="usernameError"></span><br><br>

        <label for="email">邮箱:</label>
        <input type="email" id="email" name="email">
        <span class="error" id="emailError"></span><br><br>

        <label for="password">密码:</label>
        <input type="password" id="password" name="password">
        <span class="error" id="passwordError"></span><br><br>

        <button type="submit">注册</button>
    </form>

    <script>
        $(document).ready(function() {
            $('#registerForm').on('submit', function(event) {
                let isValid = true;
                const username = $('#username').val();
                const email = $('#email').val();
                const password = $('#password').val();

                // 用户名验证
                if (username.length < 3) {
                    $('#usernameError').text('用户名至少需要3个字符');
                    isValid = false;
                } else {
                    $('#usernameError').text('');
                }

                // 邮箱验证
                const emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
                if (!emailPattern.test(email)) {
                    $('#emailError').text('请输入有效的邮箱地址');
                    isValid = false;
                } else {
                    $('#emailError').text('');
                }

                // 密码验证
                if (password.length < 6) {
                    $('#passwordError').text('密码至少需要6个字符');
                    isValid = false;
                } else {
                    $('#passwordError').text('');
                }

                if (!isValid) {
                    event.preventDefault();
                }
            });
        });
    </script>
</body>
</html>