blocks|key|1121654|text|如果只需要检查数组中是否有任何元素|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1121655|if+(empty($playerlist))+{
+++++//+list+is+empty.
}|code-block|syntax|javascript|1121656|如果您需要在检查之前清除空值(通常是为了防止explode奇怪的字符串)：|offset|length|style|CODE|1121657|foreach+($playerlist+as+$key+=>+$value)+{
++++if+(empty($value))+{
+++++++unset($playerlist[$key]);
++++}
}
if+(empty($playerlist))+{
+++//empty+array
}|1121658|entityMap^0|0|0|M|7|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

If you just need to check if there are ANY elements in the array

<pre><code>if (empty($playerlist)) {
 // list is empty.
}
</code></pre>

If you need to clean out empty values before checking (generally done to prevent <code>explode</code>ing weird strings):

<pre><code>foreach ($playerlist as $key =&gt; $value) {
 if (empty($value)) {
 unset($playerlist[$key]);
 }
}
if (empty($playerlist)) {
 //empty array
}
</code></pre>

blocks|key|1336718|text|空数组在PHP中是假的，所以你甚至不需要像其他人建议的那样使用empty()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1336719|<?php
$playerList+=+array();
if+(!$playerList)+{
++++echo+"No+players";
}+else+{
++++echo+"Explode+stuff...";
}
//+Output+is:+No+players|code-block|syntax|javascript|1336720|PHP的empty()确定一个变量是否不存在或有一个假值(如array()、0、null、false等)。|1336721|在大多数情况下，您只需要检查!$emptyVar。如果变量可能尚未设置，并且您不习惯触发E_NOTICE，则使用empty($emptyVar)；我认为这通常不是一个好主意。|1336722|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.empty.php^0|V|7|0|0|4|7|U|7|12|1|14|4|19|5|4|7|0|0|E|A|18|8|1K|G|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@$9|1B|A|1C|1|1D]]|E|$]]|$1|M|3|N|5|6|7|1E|8|@$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1L|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

An empty array is falsey in PHP, so you don't even need to use <code>empty()</code> as others have suggested.

<pre><code>&lt;?php
$playerList = array();
if (!$playerList) {
 echo "No players";
} else {
 echo "Explode stuff...";
}
// Output is: No players
</code></pre>

PHP's <a href="http://php.net/manual/en/function.empty.php" rel="noreferrer"><code>empty()</code></a> determines if a variable doesn't exist or has a falsey value (like <code>array()</code>, <code>0</code>, <code>null</code>, <code>false</code>, etc). 

In most cases you just want to check <code>!$emptyVar</code>. Use <code>empty($emptyVar)</code> if the variable might not have been set AND you don't wont to trigger an <code>E_NOTICE</code>; IMO this is generally a bad idea.

blocks|key|1121582|text|count($gamerow['players'])将为0。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1121583|entityMap|0|LINK|mutability|MUTABLE|url|http://ca.php.net/manual/en/function.count.php^0|0|Q|0|Q|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

<a href="http://ca.php.net/manual/en/function.count.php" rel="noreferrer"><code>count($gamerow['players'])</code></a> will be 0.

blocks|key|1336858|text|如果您想要确定您正在测试的变量是否确实是一个显式的空数组，您可以使用如下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1336859|if+($variableToTest+===+array())+{
++++echo+'this+is+explicitly+an+empty+array!';
}|code-block|syntax|javascript|1336860|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you want to ascertain whether the variable you are testing is actually explicitly an empty array, you could use something like this:

<pre><code>if ($variableToTest === array()) {
 echo 'this is explicitly an empty array!';
}
</code></pre>

blocks|key|1336974|text|为什么没有人回答这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1336975|$array+=+[];

if($array+==+[])+{
++++//+array+is+empty
}|code-block|syntax|javascript|1336976|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Why has no one said this answer:

<pre><code>$array = [];

if($array == []) {
 // array is empty
}
</code></pre>

blocks|key|1121780|text|如果要检查数组内容，可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1121781|$arr+=+array();

if(!empty($arr)){
++echo+"not+empty";
}
else+
{
++echo+"empty";
}|code-block|syntax|javascript|1121782|查看此处：http://codepad.org/EORE4k7v|offset|length|1121783|entityMap|0|LINK|mutability|MUTABLE|url|http://codepad.org/EORE4k7v^0|0|0|5|R|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

if you are to check the array content you may use:

<pre><code>$arr = array();

if(!empty($arr)){
 echo "not empty";
}
else 
{
 echo "empty";
}
</code></pre>

see here:
 <a href="http://codepad.org/EORE4k7v" rel="noreferrer">http://codepad.org/EORE4k7v</a>

blocks|key|1121796|text|is_array($detect)+&&+empty($detect);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1121797|is_array|unstyled|offset|length|1121798|entityMap|0|LINK|mutability|MUTABLE|url|http://www.php.net/manual/en/function.is-array.php^0|0|0|8|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@$G|S|H|T|1|U]]|A|$]]|$1|I|3|-4|5|F|7|V|8|@]|9|@]|A|$]]]|J|$K|$5|L|M|N|A|$O|P]]]]

<pre><code>is_array($detect) &amp;&amp; empty($detect);
</code></pre>

<a href="http://www.php.net/manual/en/function.is-array.php" rel="noreferrer">is_array</a>

blocks|key|1336821|text|我使用下面的代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1336822|$variable+=+array();

if(+count(+$variable+)+==+0+)
{
++++echo+"Array+is+Empty";
}
else
{
++++echo+"Array+is+not+Empty";
}|code-block|syntax|javascript|1336823|但请注意，如果数组有大量的键，则与此处的其他答案相比，此代码将花费大量时间计算这些键。|1336824|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I use this code

<pre><code>$variable = array();

if( count( $variable ) == 0 )
{
 echo "Array is Empty";
}
else
{
 echo "Array is not Empty";
}
</code></pre>

But note that if the array has a large number of keys, this code will spend much time counting them, as compared to the other answers here.

blocks|key|1121943|text|您可以使用array_filter()，它适用于所有情况：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1121944|$ray_state+=+array_filter($myarray);

if+(empty($ray_state))+{
++++echo+'array+is+empty';
}+else+{
++++echo+'array+is+not+empty';
}|code-block|syntax|javascript|1121945|entityMap^0|5|E|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You can use <code>array_filter()</code> which works great for all situations:

<pre><code>$ray_state = array_filter($myarray);

if (empty($ray_state)) {
 echo 'array is empty';
} else {
 echo 'array is not empty';
}
</code></pre>

blocks|key|1121592|text|empty($gamerow['players'])|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1121593|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>empty($gamerow['players'])
</code></pre>

blocks|key|1336886|text|+$gamerow+=+mysql_fetch_array($gameresult);

if+(!empty(($gamerow['players']))+{
+++$playerlist+=+explode(",",+$gamerow['players']);
}else{
+
++//+do+stuff+if+array+is+empty
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1336887|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> $gamerow = mysql_fetch_array($gameresult);

if (!empty(($gamerow['players'])) {
 $playerlist = explode(&quot;,&quot;, $gamerow['players']);
}else{
 
 // do stuff if array is empty
}
</code></pre>

blocks|key|1337025|text|我认为确定数组是否为空的最好方法是使用count()，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1337026|if(count($array))+{
++++return+'anything+true+goes+here';
}else+{
++++return+'anything+false';+
}|code-block|syntax|javascript|1337027|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I think the best way to determine if the array is empty or not is to use count() like so:

<pre><code>if(count($array)) {
 return 'anything true goes here';
}else {
 return 'anything false'; 
}
</code></pre>

blocks|key|1122108|text|$status+=+"";

$new_array+=+array();

if(!empty($new_array)){
++$status+=+"1";+++//+not+a+blank+array
}
else{
++$status+=+"0";+++//+blank+array
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1122109|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$status = &quot;&quot;;

$new_array = array();

if(!empty($new_array)){
 $status = &quot;1&quot;; // not a blank array
}
else{
 $status = &quot;0&quot;; // blank array
}
</code></pre>

blocks|key|1122139|text|您可以使用以下php函数来检查数组是否为空|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1122140|使用empty()函数|offset|length|style|CODE|1122141|$variable+=+array();
++++if(empty($variable)){
++++echo("The+array+is+empty.");
++++}|code-block|syntax|javascript|1122142|输出:数组为空|1122143|使用sizeof()函数|1122144|$variable+=+array();
$arraysize+=+sizeof($variable);
echo("The+size+of+the+array+is+$arraysize.+\n");
if(sizeof($variable)+==+0)
echo("The+array+is+empty.");|1122145|输出：|1122146|数组的大小为0。|1122147|数组为空。|1122148|entityMap^0|0|2|7|0|0|0|2|8|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@$D|12|E|13|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|14|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|15|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|16|8|@$D|17|E|18|F|G]]|9|@]|A|$]]|$1|Q|3|R|5|J|7|19|8|@]|9|@]|A|$K|L]]|$1|S|3|T|5|6|7|1A|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|1B|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1C|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|Z|$]]

You can use the following php functions to check whether an array is empty or not
Using <code>empty()</code> function
<pre><code>$variable = array();
 if(empty($variable)){
 echo(&quot;The array is empty.&quot;);
 }
</code></pre>
OUTPUT: The array is empty
Using <code>sizeof()</code> function
<pre><code>$variable = array();
$arraysize = sizeof($variable);
echo(&quot;The size of the array is $arraysize. \n&quot;);
if(sizeof($variable) == 0)
echo(&quot;The array is empty.&quot;);
</code></pre>
OUTPUT:
The size of the array is 0.
The array is empty.

blocks|key|1122173|text|array_filter递归和计数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1122174|function+array_filter_recursive(array+$arr)+
++{+
++++array_walk($arr,function(&$item){if+(is_array($item))++{+$item+=+array_filter_recursive($item);}});
++++return+array_filter($arr);+
++}+
+++
++function+is_empty_array(array+$arr):bool{
++++return+count(array_filter_recursive($arr))+==+0;
++}|code-block|syntax|javascript|1122175|测试|1122176|$c=['b'=>2,'c'=>3];
$a=[];
$b=[[]];
$d=['a'=>[]];
$e=['a'=>[],[]];
$f=['a'=>[[],[],[]],[]];
$g=[[[],[[],[[],[[],[]]]]],[]];
$i=[[[],[[],[[],[[],['s'=>1]]]]],[]];
var_dump(is_empty_array($c));//false
var_dump(is_empty_array($a));//true
var_dump(is_empty_array($b));//true
var_dump(is_empty_array($d));//true
var_dump(is_empty_array($e));//true
var_dump(is_empty_array($f));//true
var_dump(is_empty_array($g));//true
var_dump(is_empty_array($i));//false|1122177|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

array_filter recursive and count
<pre><code>function array_filter_recursive(array $arr) 
 { 
 array_walk($arr,function(&amp;$item){if (is_array($item)) { $item = array_filter_recursive($item);}});
 return array_filter($arr); 
 } 
 
 function is_empty_array(array $arr):bool{
 return count(array_filter_recursive($arr)) == 0;
 }
</code></pre>
test
<pre><code>$c=['b'=&gt;2,'c'=&gt;3];
$a=[];
$b=[[]];
$d=['a'=&gt;[]];
$e=['a'=&gt;[],[]];
$f=['a'=&gt;[[],[],[]],[]];
$g=[[[],[[],[[],[[],[]]]]],[]];
$i=[[[],[[],[[],[[],['s'=&gt;1]]]]],[]];
var_dump(is_empty_array($c));//false
var_dump(is_empty_array($a));//true
var_dump(is_empty_array($b));//true
var_dump(is_empty_array($d));//true
var_dump(is_empty_array($e));//true
var_dump(is_empty_array($f));//true
var_dump(is_empty_array($g));//true
var_dump(is_empty_array($i));//false
</code></pre>

blocks|key|1122063|text|我已经用下面的代码解决了这个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1122064|$catArray=array();++++++++++++++++++++++++++

$catIds=explode(',',$member['cat_id']);
if(!empty($catIds[0])){
foreach($catIds+as+$cat_id){
$catDetail=$this->Front_Category->get_category_detail($cat_id);
$catArray[]=$catDetail['allData']['cat_title'];
}
echo+implode(',',$catArray);
}|code-block|syntax|javascript|1122065|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I have solved this issue with following code.

<pre><code>$catArray=array(); 

$catIds=explode(',',$member['cat_id']);
if(!empty($catIds[0])){
foreach($catIds as $cat_id){
$catDetail=$this-&gt;Front_Category-&gt;get_category_detail($cat_id);
$catArray[]=$catDetail['allData']['cat_title'];
}
echo implode(',',$catArray);
}
</code></pre>

blocks|key|1122097|text|这似乎对所有情况都有效。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1122098|if(!empty(sizeof($array)))|code-block|syntax|javascript|1122099|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This seems working for all cases

<pre><code>if(!empty(sizeof($array)))
</code></pre>

<code>players</code> will either be empty or a comma separated list (or a single value). What is the easiest way to check if it's empty? I'm assuming I can do so as soon as I fetch the <code>$gameresult</code> array into <code>$gamerow</code>? In this case it would probably be more efficient to skip exploding the <code>$playerlist</code> if it's empty, but for the sake of argument, how would I check if an array is empty as well?

<pre><code>$gamerow = mysql_fetch_array($gameresult);
$playerlist = explode(",", $gamerow['players']);
</code></pre>

How to check whether an array is empty using PHP?

players将为空或逗号分隔的列表(或单个值)。检查它是否为空的最简单方法是什么？我假设我可以在将$gameresult数组提取到$gamerow中后立即执行此操作？在这种情况下，如果$playerlist是空的，那么跳过分解它可能会更有效，但是为了便于讨论，我如何检查数组是否也是空的？$gamerow = mysql_fetch_array($gameresult);$playerlist =

问如何使用PHP检查数组是否为空？
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回答 17

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问如何使用PHP检查数组是否为空？EN

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问如何使用PHP检查数组是否为空？
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