Correct use of each() function in php

The each() function in php is to return the current key/value pair in the array and move the array pointer forward In the first step, this article will take everyone to take a look at how to use this function. The first thing to look at is naturally its syntax:

each  ( array $arr)

• $arr: the input array.

• Return value: array array, returns the key/value pair of the current pointer position in the array array and moves the array pointer forward. Key-value pairs are returned as a four-element array with key names 0, 1, key, and value. Cells 0 and key contain the key names of the array cells, and 1 and value contain the data. If the internal pointer is past the end of the array, each() returns false.

Code example:

1. Use alone

<?php
$arr=array("法外狂徒"=>"张三","阳光少年"=>"龙之介","热心市民"=>"金闪闪","纯爱战士"=>"。。。");
print_r(each($arr));
?>

输出：Array ( [1] => 张三 [value] => 张三 [0] => 法外狂徒 [key] => 法外狂徒 )

Note: This The function has been deprecated since PHP 7.2.0. If used, it will prompt: Deprecated: The each() function is deprecated. This message will be suppressed on further calls in F:\learnlog\zend\php\each.php on line 3.

2. Traverse the array with list

<?php
$arr=array("法外狂徒"=>"张三","阳光少年"=>"龙之介","热心市民"=>"金闪闪","纯爱战士"=>"。。。");

while (list($key, $val) = each($arr)) {
    echo "$key => $val;<br>";
}
?>

输出： 法外狂徒 => 张三;
       阳光少年 => 龙之介;
       热心市民 => 金闪闪;
       纯爱战士 => 。。。;

Note: Because assigning an array to another array will reset the original array pointer , so in the above example, if $arr is assigned to another variable inside the loop, it will cause an infinite loop.

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