What is the function of list in php

list() is used to assign values ​​to a set of variables in one operation.

Note: list() is only used for numerically indexed arrays, and it is assumed that numerical indexing starts from 0.

Description

list() assigns a value to a set of variables using elements in the array.

Note that, similar to array(), list() is actually a language structure, not a function.

Related recommendations: "PHP Getting Started Tutorial"

For example:

<?php
　　$my_array = array(&#39;Dog&#39;,&#39;Cat&#39;,&#39;Horse&#39;);
　　list($a, $b, $c) = $my_array;
　　echo &#39;I have several animals, a &#39;.$a.&#39;, a &#39;.$b.&#39; and a &#39;.$c;
?>

The result is as follows, which can be output normally

When the array is not a numeric array but an associative array, such as:

<?php
$my_array = array(&#39;a&#39;=>&#39;Dog&#39;,&#39;b&#39;=>&#39;Cat&#39;,&#39;c&#39;=>&#39;Horse&#39;);
list($a, $b, $c) = $my_array;
echo &#39;I have several animals, a &#39;.$a.&#39;, a &#39;.$b.&#39; and a &#39;.$c;
?>

The result will be an error

When using the index array is For example:

<?php
　　$my_array = array(0=>&#39;Dog&#39;,1=>&#39;Cat&#39;,2=>&#39;Horse&#39;);
　　list($a, $b, $c) = $my_array;
　　echo &#39;I have several animals, a &#39;.$a.&#39;, a &#39;.$b.&#39; and a &#39;.$c;
?>

This can be output normally. When the code is changed to:

<?php
$my_array = array(1=>&#39;Dog&#39;,2=>&#39;Cat&#39;,3=>&#39;Horse&#39;);
list($a, $b, $c) = $my_array;
echo &#39;I have several animals, a &#39;.$a.&#39;, a &#39;.$b.&#39; and a &#39;.$c;
?>

, the output result is as follows:

The variable $a is merged It is not assigned, and the element with subscript 1 is assigned to the second variable $b. That is to say, the first element in list() is assigned with subscript 0, and the second element is assigned with subscript 1. Assignment, the third element is assigned with index 2, and so on.

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