php 如何检查 $_GET 是否为空？
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How to check if $_GET is empty?
提问by Vamsi Krishna B
How to check if $_GETis empty?
如何检查是否$_GET为空？
回答by NikiC
You said it yourself, check that it's empty:
你自己说的，检查它是empty：
if (empty($_GET)) {
// no data passed by get
}
See, PHP is so straightforward. You may simply write, what you think ;)
看，PHP 是如此简单。你可以简单地写下你的想法;)
This method is quite secure. !$_GETcould give you an undefined variable E_NOTICE if $_GETwas unset (not probable, but possible).
这种方法非常安全。!$_GET如果$_GET未设置（不太可能，但可能），可能会给你一个未定义的变量 E_NOTICE 。
回答by sherilyn
i guess the simplest way which doesn't require any operators is
我想不需要任何操作员的最简单的方法是
if($_GET){
//do something if $_GET is set
}
if(!$_GET){
//do something if $_GET is NOT set
}
回答by Pekka
Just to provide some variation here: You could check for
只是在这里提供一些变化：您可以检查
if ($_SERVER["QUERY_STRING"] == null)
it is completely identical to testing $_GET.
它与测试完全相同$_GET。
回答by john010117
<?php
if (!isset($_GET) || empty($_GET))
{
// do stuff here
}
回答by Your Common Sense
if (!$_GET) echo "empty";
why do you need such a checking?
为什么需要这样的检查？
lol
you guys too direct-minded.
don't take as offense but sometimes not-minded at all
$_GET is very special variable, not like others.
it is supposed to be always set. no need to treat it as other variables.
when $_GET is not set and it's expected - it is emergencycase and that's what "Undefined variable" notice invented for
大声笑
你们太直接了。
不要冒犯但有时根本不介意
$_GET 是非常特殊的变量，不像其他变量。
它应该总是被设置。无需将其视为其他变量。当 $_GET 未设置并且是预期的 - 这是紧急情况，这就是发明的“未定义变量”通知
回答by Martin Bean
Easy.
简单。
if (empty($_GET)) {
// $_GET is empty
}
回答by Martin Bean
Here are 3 different methods to check this
这里有 3 种不同的方法来检查这个
<?php
//Method 1
if(!empty($_GET))
echo "exist";
else
echo "do not exist";
//Method 2
echo "<br>";
if($_GET)
echo "exist";
else
echo "do not exist";
//Method 3
if(count($_GET))
echo "exist";
else
echo "do not exist";
?>
回答by vlad b.
I would use the following if statement because it is easier to read (and modify in the future)
我将使用以下 if 语句，因为它更易于阅读（并在将来进行修改）
if(!isset($_GET) || !is_array($_GET) || count($_GET)==0) {
// empty, let's make sure it's an empty array for further reference
$_GET=array();
// or unset it
// or set it to null
// etc...
}
