php - 不使用$ _GET 'Undefined Index']格式时如何解决[''错误？

Question

我正在编写用于登录密码恢复的代码，因此，我需要一个名为“recoverykey”的$ _GET值。每当我访问网页时未定义 recoverykey 时，它就会告诉我未定义索引错误。当然，会发生错误，但是我不需要表达 recoverykey 的值，那么如何删除该错误？

当我使用url时，错误看起来像这样: localhost/websites/index.php



当我在url上时，该错误消失: localhost/websites/index.php？recoverykey = 39238579857

代码如下:

<?php

        $change_code = $_GET['recoverykey'];

        $sqlQuery = "SELECT * FROM RegisteredMembers WHERE RecoveryCode='$change_code'";
        $result = mysqli_query($conn,$sqlQuery);
        $fetch_result = mysqli_fetch_array($result);
        $row_count = mysqli_num_rows($result);
        if($row_count==1 && !$change_code==0){

                $error = false;

                $passError = null;
                $output = null;
                $errorMsg = null;

                if(isset($_POST['btn-changepass-submit'])){

                    $password = $_POST['change-pass'];

                    // Password Validation
                    if(empty($password)){
                        $error = true;
                        $passError = "Please write your new password.";
                    } else if(strlen($password)<8){
                        $error = true;
                        $passError = "Passwords should atleast be 8 chars long.";
                    }

                    // If no error, continue
                    if(!$error){
                        /*$fetch_result['userEmail'] = $email;*/
                        $dtbQuery = "UPDATE RegisteredMembers SET password='$password' WHERE RecoveryCode='$change_code'";
                        $new_result = mysqli_query($conn,$dtbQuery);
                        if($new_result){
                            $errorType = "success";
                            $errorMsg = "Successfully changed password. <a href=#login-login>Login here</a>.";

                            $dbQuery = "UPDATE RegisteredMembers SET RecoveryCode='0' WHERE RecoveryCode='$change_code'";
                            $new_output = mysqli_query($conn,$dbQuery);

                        } else{
                            $errorType = "danger";
                            $errorMsg = "There seems to be an error. Please try again!";
                        }
                    }

                }

                ?>
                    <div id="login-passchange">
                        <h2>Change your Password</h2>
                        <form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>?recoverykey=<?php echo $change_code ?>#login-passchange">
                            <span class="<?php echo $errorType; ?>-msg">
                                <?php
                                    if($output){
                                        echo $errorMsg;
                                    } else{
                                        echo $errorMsg;
                                    }
                                ?>
                            </span>
                            <label><span class="danger-msg"><?php echo $passError; ?></span><input type="password" placeholder="Write your New Password" maxlength="255" name="change-pass" required /></label>
                            <input type="submit" value="Set new Password" name="btn-changepass-submit" />
                        </form>
                        <div class="lower-part">
                            <a class="login-link" href="#login-login">Password Found? Login</a>
                            <br />
                            <a class="home-link" href="#home">Go back</a>
                        </div>
                    </div>
                <?php
        } else{
            ?>
                <div id="login-passchange">
                        <h2>Error 404!</h2>
                </div>
            <?php
        }

    ?>

该代码在更改密码方面取得了成功，但是我不希望出现该错误消息。此外，我尝试在StackOverflow上找到此问题，但该问题没有具体答案。因此，它永远不会重复。

在此先感谢您的帮助!

Answer 1

用这个

$change_code = isset($_GET['recoverykey']) ? $_GET['recoverykey'] : '';