PHP empty Keyword

Example

Check if a variable is empty:

<?php
$str = "";
if(empty($str)) {
echo "The string is empty";
}
?>

Definition and Usage

The empty keyword acts as a function which returns true if a variable does not exist, or if its value is considered empty. The empty keyword also evaluates expressions which are not in a variable.

A value is considered empty if its value is any of the following:

An empty string
An empty array
The integer 0
The floating point number 0.0
The string "0"
Boolean false
null

More Examples

Example

Use empty on a variety of different expressions:

<?php
// A variable that does not exist
if(empty($x)) {
echo '$x does not exist ';
}

// An empty integer
if(empty(0)) {
echo '0 is empty ';
}

// An empty float
if(empty(0.0)) {
echo '0.0 is empty ';
}

// An empty string
if(empty("")) {
echo '"" is an empty string ';
}

// null
if(empty(null)) {
echo 'null is empty ';
}

// A value that is not empty
if(empty('A')) {
echo '"A" is empty ';
} else {
echo '"A" is not empty ';
}
?>

Try it Yourself »

❮ PHP Keywords