How to remove duplicate and empty elements from php array

Implementation steps: 1. Use the array_unique() function to remove duplicate elements in the original array. The syntax "array_unique (original array)" will return a deduplicated array; 2. Use the array_filter() function to filter and deduplicate. Array, just delete the empty elements in the deduplication array, the syntax is "array_filter (deduplication array)".

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

In php, you can use the array_unique() function and The array_filter() function is used to remove duplicate and empty elements in the array

• array_unique() function is used to remove duplicates

• array_filter() function is used To remove empty elements

Implementation steps:

1. Use the array_unique() function to remove duplicate elements from the array

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array("php",11,12,&#39;&#39;,12,"javascript",2022,"php","mysql"); 
var_dump($arr);
$res=array_unique($arr);
var_dump($res);
?>

2. Use the array_filter() function to delete empty elements in the deduplicated array

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array("php",11,12,&#39;&#39;,null,12,"javascript",2022,"php","mysql"); 
var_dump($arr);
$res=array_unique($arr);
var_dump($res);

var_dump(array_filter($res));
?>

Instructions:

1. array_unique() function

array_unique -- remove duplicate values ​​in the array

The syntax format is as follows:

array array_unique ( array array )

array_unique() accepts an array as input and returns a new array with no duplicate values

Note that the key names remain unchanged. array_unique() sorts the values ​​first as strings, then retains only the first encountered key for each value, and then ignores all subsequent keys. This does not mean that the first occurrence of the same value in an unsorted array will be preserved.

Note: Two units are considered the same if and only if (string) $elem1 === (string) $elem2. That is, when the expressions of the strings are the same. The first unit will be retained.

2. array_filter() function

The array_filter() function, also known as the callback function, is used to filter the elements of the array using a user-defined function. It iterates over each value in the array, passing them to a user-defined function or callback function.

When the array_filter() function is used to declare a callback function, it will delete false values, however, If the callback function is not specified, all values ​​in the array that are equal to FALSE, such as the empty string, will be deleted or NULL value.

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