How to use empty function in php

The method of using empty function in php is [bool empty (mixed $var)]. The empty() function is used to check whether a variable is empty. If the variable does not exist or the value is equal to false, it will be considered not to exist.

The operating environment of this article: windows10 system, php 7.3, thinkpad t480 computer.

The empty() function in php is used to check whether a variable is empty. empty() determines whether a variable is considered empty. When a variable does not exist, or its value is equal to FALSE, then it is considered not to exist. empty() does not generate a warning if the variable does not exist.

empty() After version 5.5, it supports expressions, not just variables.

Syntax structure:

bool empty ( mixed $var )

Example:

<?php
$ivar1=0;
$istr1=&#39;phpcncncn&#39;;
if (empty($ivar1)){
    echo &#39;$ivar1&#39; . " 为空或为 0。" . PHP_EOL;
}else{
    echo &#39;$ivar1&#39; . " 不为空或不为 0。" . PHP_EOL;
}if (empty($istr1)){
    echo &#39;$istr1&#39; . " 为空或为 0。" . PHP_EOL;
}else{
    echo &#39;$istr1&#39; . " 字符串不为空或不为0。" . PHP_EOL;
}
?>

Running result:

$ivar1 is empty or 0.

$istr1 The string is not empty or 0.

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