PHP array learning to randomly obtain multiple elements

In the previous article, we introduced the method of randomly shuffling array elements. If you are interested, you can click to read → "PHP Array Learning: Random Sorting, Shuffling Array Elements". In the following article, we will take a look at randomness and introduce how to randomly obtain one or more array elements.

In fact, there is an array function array_rand() in PHP. Its function is to obtain randomly, but it can only obtain one or more array key names, but cannot obtain key values.

Although array_rand() cannot directly obtain the array key value, we use the random key name obtained by array_rand() and add a few more lines of code to achieve random acquisition of elements (both key name and key value).

Let’s take a look at the implementation code:

<?php
$arr=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$rand = array_rand($arr);
$arr2[$rand]=$arr[$rand];
var_dump($arr2);
?>

Output result:

It can be seen that: we only get it randomly An element, because the array_rand($arr) statement can only randomly obtain one key name, so how to obtain multiple key names?

You only need to set two parameters to the array_rand() function. The first parameter $array specifies the array, and the second parameter $number specifies the number to be obtained. The number of key names.

<?php
$arr=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$rand = array_rand($arr,3);
foreach($rand as $val){
	$arr2[$val]=$arr[$val];
}
var_dump($arr2);
?>

When the array_rand() function obtains multiple key names, it will return an array containing random key names.

In this way, we can use the foreach statement to traverse the $rands array, and continuously start from $arrs based on the key names in the $rands array. Just get the value from the array and assign it to the new array $arr2. Let’s take a look at the output:

Refresh and the result will change:

Note: array_rand() If the number obtained ($number) exceeds the length of $array, an E_WARNING error will occur and NULL will be returned.

Okay, that’s all. If you want to know anything else, you can click this. → →php video tutorial

Finally, I would like to recommend a free video tutorial on PHP arrays: PHP function array array function video explanation, come and learn!

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