In this tutorial we will learn How To Check if Variable is Null in PHP. PHP is_null() function is a built-in function which can be used to check whether a variable is null or not.
Table of Contents
PHP is_null() Function
PHP is_null() Function is used to check if a variable is null or not.
is_null() function returns 1 if variable is null and 0 if it is not.
Variable is NULL if it has no value or if it has been assigned NULL.
<?php
$variable ='HowToCodeSchool.com';
if (is_null($variable))
{
echo "Variable is NULL";
}
else
{
echo "Variable is not NULL";
}
?>
In above code since variable has a string as it's value so it won't be called as NULL variable.
<?php
$variable = NULL;
if (is_null($variable))
{
echo "Variable is NULL";
}
else
{
echo "Variable is not NULL";
}
?>
While in second example, variable is a NULL variable.
<?php
if (is_null($variable))
{
echo "Variable is NULL";
}
else
{
echo "Variable is not NULL";
}
?>
In this third example, "Variable is NULL" will be printed since the variable we are checking doesn't exist.