How to detect if an array is empty in php

3 detection methods: 1. Use "===" to determine whether the specified array is equal to "[]", the syntax is "$arr===[]", if the return value is TRUE, it will be empty , if the return value is FALSE, it is not empty. 2. Use empty() detection, the syntax is "empty($arr)", if the specified array is empty, TRUE is returned, otherwise FALSE is returned. 3. Use count() to get the length of the array, and just check whether the length of the array is greater than 0. The syntax is "count($arr)>0". If it is greater, it is not empty.

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

php Three methods to detect whether an array is empty (whether it is an empty array)

Method 1: Use the "===" operator to detect

You only need to determine whether the specified array is equal to "[]". If it is equal, it will be an empty array (the return value is TRUE if it is empty, and if the return value is FALSE it is not empty).

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$arr=array();
var_dump($arr);
if($arr===[]){
	echo "指定数组为空";
}else{
	echo "指定数组不为空<br";
}
?>

Method 2: Use the empty() function to detect

The empty() function is used to check whether a variable is empty. Returns TRUE if the specified array is empty, otherwise returns FALSE.

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$arr=array(1,2,3);
var_dump($arr);
if(empty($arr)){
	echo "指定数组为空";
}else{
	echo "指定数组不为空<br";
}
?>

Method 3: Use the count() function to detect

The count() function can return the array length. If the array length is equal to 0, the specified array is empty; otherwise if the array length is greater than 0, the specified array is not empty

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$arr=array(1);
var_dump($arr);
if(count($arr)>0){
	echo "指定数组不为空";
}else{
	echo "指定数组为空<br";
}
?>

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