How to use each method in php

How to use each method in php?

each definition and usage

each() function returns the key name and key value of the current element, and moves the internal pointer backward.

The key name and key value of the element are returned to an array with four elements. Two elements (1 and Value) contain the key value, and two elements (0 and Key) contain the key name.

Related methods:

current() - 返回数组中的当前元素的值。
end() - 将内部指针指向数组中的最后一个元素，并输出。
next() - 将内部指针指向数组中的下一个元素，并输出。
prev() - 将内部指针指向数组中的上一个元素，并输出。
reset() - 将内部指针指向数组中的第一个元素，并输出。

Tip: The each() function is deprecated in PHP 7.2.0.

Syntax

each(array)

Parameters

array required. Specifies the array to use.

Return value: Returns the key name and key value of the current element. The element's key name and value are returned in an array with four elements. Two elements (1 and Value) contain the key value, and two elements (0 and Key) contain the key name. If there are no more array elements, the function returns FALSE.

Example 1

Same as the example at the top of the page, but this example outputs the entire array through a loop:

<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");
 
reset($people);
 
while (list($key, $val) = each($people))
{
    echo "$key => $val<br>";
}
?>

Running result:

0 => Peter
1 => Joe
2 => Glenn
3 => Cleveland

Example 2

Demonstration of all related methods:

<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");
 
echo current($people) . "<br>"; // The current element is Peter
echo next($people) . "<br>"; // The next element of Peter is Joe
echo current($people) . "<br>"; // Now the current element is Joe
echo prev($people) . "<br>"; // The previous element of Joe is Peter
echo end($people) . "<br>"; // The last element is Cleveland
echo prev($people) . "<br>"; // The previous element of Cleveland is Glenn
echo current($people) . "<br>"; // Now the current element is Glenn
echo reset($people) . "<br>"; // Moves the internal pointer to the first element of the array, which is Peter
echo next($people) . "<br>"; // The next element of Peter is Joe
 
print_r (each($people)); // Returns the key and value of the current element (now Joe), and moves the internal pointer forward
?>

Running results:

Peter
Joe
Joe
Peter
Cleveland
Glenn
Glenn
Peter
Joe

Array ( [1] => Joe [value] => Joe [0] => 1 [key] => 1 )

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