检查“不为空"的PHP语法是什么?还是一个空字符串? [英] What is the PHP syntax to check "is not null" or an empty string?

问题描述

可能重复:
检查变量是否为空

Possible Duplicate:
Check if a variable is empty

一个简单的PHP问题:

Simple PHP question:

我有这句话:

if (isset($_POST["password"]) && ($_POST["password"]=="$password")) {
...//IF PASSWORD IS CORRECT STUFF WILL HAPPEN HERE
}

在此语句的上方，我在JavaScript中使用以下行将用户名设置为JavaScript和PHP中的变量:

Somewhere above this statement I use the following line in my JavaScript to set the username as a variable both in my JavaScript and in my PHP:

uservariable = <?php $user = $_POST['user']; print ("\"" . $user . "\"")?>;

我想做的是添加一个条件，以确保$ user不为null或为空字符串(它不必为任何特定值，我只是不希望它为空.正确的方法吗?

What I want to do is add a condition to make sure $user is not null or an empty string (it doesn't have to be any particular value, I just don't want it to be empty. What is the proper way to do this?

我知道这是一个棘手的问题，但是我没有使用PHP的经验.请指教，谢谢！

I know this is a sill question but I have no experience with PHP. Please advise, Thank you!

推荐答案

是空还是空字符串?

if (!empty($user)) {}

使用empty().

意识到$ user〜= $ _POST ['user'](感谢matt)之后:

After realizing that $user ~= $_POST['user'] (thanks matt):

var uservariable='<?php 
    echo ((array_key_exists('user',$_POST)) || (!empty($_POST['user']))) ? $_POST['user'] : 'Empty Username Input';
?>';

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