初学者php“警告:未定义的数组键" [英] Beginner php "Warning: Undefined array key"

问题描述

因此，我正在学习PHP，并且不断收到警告:未定义的数组键".在$ GET _ ["fname"]和$ GET _ ["age"]中:

So, I'm learning PHP and I keep getting "Warning: Undefined array key" in $GET_["fname"] and $GET_["age"]:

<main>

    <form action="inputs.php" method="get">
        Name: 
        <br/>
        <input type="text" name="fname">
        <br/>
        Age:
        <br/>
        <input type="number" name="age">
        <br/>
        <input type="submit" name="submit">

    </form>
        <br/>
        Your name is <?php echo $_GET["fname"]; ?>
        <br/>
        Your age is <?php echo $_GET["age"]; ?>

</main>

推荐答案

我假设您想知道如何摆脱此错误消息.

I'll assume you want to know how to get rid of this error message.

第一次加载此页面时，将显示一个表单，并且$ _GET为空(这就是它触发警告的原因).然后，您提交表单，并将fname和age参数添加到url中(因为表单的方法是'get').

The first time you load this page you display a form and $_GET is empty (that's why it is triggering warnings). Then you submit the form and the fname and age parameters will be added to the url (because your form's method is 'get').

要解决您的问题，您可以将两行换成一些if语句，例如:

To resolve your issue you could wrap the two lines inside some if-statement, for example:

<?php if(isset($_GET['fname']) && isset($_GET['age'])): ?>
        <br/>
        Your name is <?php echo $_GET["fname"]; ?>
        <br/>
        Your age is <?php echo $_GET["age"]; ?>
<?php endif; ?>

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