blocks|key|1406293|text|使用函数array_unshift|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1406294|entityMap|0|LINK|mutability|MUTABLE|url|http://www.php.net/manual/en/function.array-unshift.php^0|4|D|4|D|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]]]]

Use function <a href="http://www.php.net/manual/en/function.array-unshift.php" rel="noreferrer"><code>array_unshift</code></a>

blocks|key|1406301|text|使用array_unshift($array,+$item);|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1406302|$arr+=+array('item2',+'item3',+'item4');
array_unshift($arr+,+'item1');
print_r($arr);|code-block|syntax|javascript|1406303|会给你带来|1406304|Array
(
+[0]+=>+item1
+[1]+=>+item2
+[2]+=>+item3
+[3]+=>+item4
)|1406305|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.array-unshift.php^0|2|T|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

Use <a href="http://php.net/manual/en/function.array-unshift.php" rel="noreferrer">array_unshift($array, $item);</a>

<pre><code>$arr = array('item2', 'item3', 'item4');
array_unshift($arr , 'item1');
print_r($arr);
</code></pre>

will give you

<pre><code>Array
(
 [0] =&gt; item1
 [1] =&gt; item2
 [2] =&gt; item3
 [3] =&gt; item4
)
</code></pre>

blocks|key|1190916|text|这会有帮助的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1190917|http://www.w3schools.com/php/func_array_unshift.asp|offset|length|1190918|array_unshift();|code-block|syntax|javascript|1190919|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1F|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@$D|T|E|U|1|V]]|A|$]]|$1|F|3|G|5|H|7|W|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|C]]]]

This will help

<a href="http://www.w3schools.com/php/func_array_unshift.asp" rel="nofollow noreferrer">http://www.w3schools.com/php/func_array_unshift.asp</a>

<pre><code>array_unshift();
</code></pre>

blocks|key|1406425|text|如果是不想更改数组键的关联数组或编号数组：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1406426|$firstItem+=+array('foo'+=>+'bar');

$arr+=+$firstItem+%2B+$arr;|code-block|syntax|javascript|1406427|array_merge不起作用，因为它总是对数组重新编制索引。|offset|length|style|CODE|1406428|entityMap^0|0|0|0|B|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

In case of an associative array or numbered array where you do not want to change the array keys:

<pre><code>$firstItem = array('foo' =&gt; 'bar');

$arr = $firstItem + $arr;
</code></pre>

<code>array_merge</code> does not work as it always reindexes the array.

blocks|key|1191097|text|或者您可以使用临时数组，然后删除真实数组，如果您想在周期中更改它：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1191098|$array+=+array(0+=>+'a',+1+=>+'b',+2+=>+'c');
$temp_array+=+$array[1];

unset($array[1]);
array_unshift($array+,+$temp_array);|code-block|syntax|javascript|1191099|输出将为：|1191100|array(0+=>+'b',+1+=>+'a',+2+=>+'c')|1191101|当我们在循环中这样做的时候，你应该在将项目添加到数组之后清除$temp_array。|offset|length|style|CODE|1191102|entityMap^0|0|0|0|0|U|B|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]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Or you can use temporary array and then delete the real one if you want to change it while in cycle:

<pre><code>$array = array(0 =&gt; 'a', 1 =&gt; 'b', 2 =&gt; 'c');
$temp_array = $array[1];

unset($array[1]);
array_unshift($array , $temp_array);
</code></pre>

the output will be:

<pre><code>array(0 =&gt; 'b', 1 =&gt; 'a', 2 =&gt; 'c')
</code></pre>

and when are doing it while in cycle, you should clean <code>$temp_array</code> after appending item to array.

blocks|key|1406532|text|使用自定义索引：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1406533|$arr=array("a"=>"one",+"b"=>"two");
++++$arr=array("c"=>"three",+"d"=>"four").$arr;

++++print_r($arr);
++++-------------------
++++output:
++++----------------
++++Array
++++(
++++[c]=["three"]
++++[d]=["four"]
++++[a]=["two"]
++++[b]=["one"]
++++)|code-block|syntax|javascript|1406534|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|$]]

<h2>With custom index:</h2>

<pre><code>$arr=array("a"=&gt;"one", "b"=&gt;"two");
 $arr=array("c"=&gt;"three", "d"=&gt;"four").$arr;

 print_r($arr);
 -------------------
 output:
 ----------------
 Array
 (
 [c]=["three"]
 [d]=["four"]
 [a]=["two"]
 [b]=["one"]
 )
</code></pre>

blocks|key|1406576|text|对于关联数组，只需使用merge即可。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1406577|$arr+=+array('item2',+'item3',+'item4');
$arr+=+array_merge(array('item1'),+$arr)|code-block|syntax|javascript|1406578|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|$]]

For an associative array you can just use merge.

<pre><code>$arr = array('item2', 'item3', 'item4');
$arr = array_merge(array('item1'), $arr)
</code></pre>

I know how to insert it to the end by:

<pre><code>$arr[] = $item;
</code></pre>

But how to insert it to the beginning?

How to insert an item at the beginning of an array in PHP?

我知道如何将它插入到末尾，方法是：$arr[] = $item;但是如何把它插入到开头呢？

问在PHP中如何在数组的开头插入一项？
EN

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问在PHP中如何在数组的开头插入一项？
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