关联数组中的变量问题 [英] Problems with variables in associative arrays

问题描述

如果用户未填写该字段，我希望使用默认字符串作为关联数组的值。例如未插入。如果用户填写该字段，则变量应采用用户输入的值。所以我写了这段代码：

I would like to have default string as values of an associative array if a user didn't fill in the field. For example "not inserted". If a user fills in the field, a variable should take the value the user put. So I wrote this code:

<?php
if (isset($_POST['submit'])){
    if (isset($_POST['name'])){
        $name =$_POST['name'];     
} else {
        $name = "not inserted";
}
if (isset($_POST['surname'])){
    $surname =$_POST['surname']; 
} else {
    $surname = "not inserted";
}
if (isset($_POST['job'])) { 
    $job = $_POST['job'];
} else {
   $job = "not inserted";
}
    $data = array('name'=>$name, 'surname'=>$surname, 'job'=>$job);
    print_r($data);
}
?>

<form action="" method="post">

<input type="text" id="name" name="name"/>
<input type="text" id="surname" name="surname"/>
<input type="text" id="job" name="job"/>
<input type="submit" id="submit" name="submit"/>

</form>

但是如果我不填写某些字段而不是未插入，则字符串print_r向我显示以下结果：

But if I don't fill in some field instead of "not inserted" string print_r shows me the following result:

Array ( [name] => [surname] => [job] => )

请，有人可以告诉我我哪里出错了吗？谢谢。

Please, can someone tell me where did I go wrong? Thanks.

推荐答案

空白输入仍会张贴到表单操作页面上，即使它们没有内容。因此，如果在所有字段都保留为空的情况下使用 var_dump（$ _ POST），您会看到类似以下内容：

Blank inputs are still posted to a forms action page, even if they have no content. So if you were to var_dump($_POST) when leaving all your fields empty, you'd see something like this:

array (size=3)
  'name' => string '' (length=0)
  'surname' => string '' (length=0)
  'job' => string '' (length=0)
  ...

它们是设置（即它们存在）但为空。您可以使用 empty（）函数检查其中是否存在值：

They are set (i.e. they exist) but are empty. You can check if there is a value in there using the empty() function like this:

if (!empty($_POST['name'])) {
    $name = $_POST['name'];
} else {
    $name = "not inserted";
}
if (!empty($_POST['name'])) {
    $name = $_POST['name'];
} else {
    $name = "not inserted";
}
if (!empty($_POST['job'])) {
    $name = $_POST['job'];
} else {
    $name = "not inserted";
}

详细了解如何空在文档中起作用。

Read more about how empty works in the documentation.

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