How to determine whether array elements are empty in php

Implementation steps: 1. Use the array_filter() function to filter the array and delete the empty elements in the array. The syntax "array_filter (original array)" will return a filtered array; 2. Use count() The function obtains the length of the original array and the length of the filtered array; 3. Check whether the lengths of the two obtained arrays are equal. The syntax is "original array length === filtered array length". If they are equal, the array elements are not empty, and vice versa. Some array elements are empty.

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

In php, you can use the array_filter() function and count() determine that none of the array elements are empty.

Implementation idea:

• Use the array_filter() function to delete empty elements in the array

• Use the count() function to obtain the original array length and the processed array length, and determine whether the two lengths are equal

Implementation steps:

1. Use the array_filter() function to filter the array and delete empty elements in the array.

The array_filter() function, also known as the callback function, is used to filter the array using user-defined functions. Elements. 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 ​​(null values), but if the callback function is not specified, all values ​​equal to FALSE in the array will be deleted, such as the null character String or NULL value.

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array(11,&#39;&#39;,null,12,false,0); 
var_dump($arr);
$newarr = array_filter($arr); 
echo "过滤后的数组：";
var_dump($newarr);
?>

2. Use the count() function to obtain the length of the original array and the length of the filtered array

$len1=count($arr);
$len2=count($newarr);

3. Determine whether the two lengths are equal

• If the two lengths are equal, the empty elements are not deleted, that is, none of the array elements are empty

• If the two lengths are not equal, the empty elements are deleted, that is, some array elements are empty

$len1=count($arr);
$len2=count($newarr);
if($len1===$len2){
	echo "数组元素均不为空值";
}
else{
	echo "有数组元素为空值";
}

Implementation example code:

<?php
header("Content-type:text/html;charset=utf-8");
function f($arr){
	$len1=count($arr);
	$newarr = array_filter($arr); 
	$len2=count($newarr);
	if($len1===$len2){
		echo "数组元素均不为空值<br>";
	}else{
		echo "有数组元素为空值<br>";
	}
}


$arr1 = array(11,&#39;&#39;,null,12,false,0); 
var_dump($arr1);
f($arr1);

$arr2 = array(1,2,3,4,5,6); 
var_dump($arr2);
f($arr2);
?>

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