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How to check whether a variable is empty in PHP
Topic: PHP / MySQLPrev|Next
Answer: Use the PHP empty() function
You can use the PHP empty() function to find out whether a variable is empty or not. A variable is considered empty if it does not exist or if its value equals FALSE.
Let's try out the following example to understand how this function basically works:
Example
Try this code »<?php
$var1 = '';
$var2 = 0;
$var3 = NULL;
$var4 = FALSE;
$var5 = array();
// Testing the variables
if(empty($var1)){
echo 'This line is printed, because the $var1 is empty.';
}
echo "<br>";
if(empty($var2)){
echo 'This line is printed, because the $var2 is empty.';
}
echo "<br>";
if(empty($var3)){
echo 'This line is printed, because the $var3 is empty.';
}
echo "<br>";
if(empty($var4)){
echo 'This line is printed, because the $var4 is empty.';
}
echo "<br>";
if(empty($var5)){
echo 'This line is printed, because the $var5 is empty.';
}
?>Note: The empty() function does not generate a warning if the variable does not exist. That means empty() is equivalent to !isset($var) || $var == false.
Related FAQ
Here are some more FAQ related to this topic:
- How to check whether a variable is set or not in PHP
- How to check whether a variable is null in PHP
- How to check if a value exists in an array in PHP
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