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PHP empty Keyword

❮ PHP Keywords


Check if a variable is empty:

$str = "";
if(empty($str)) {
  echo "The string is empty";
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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


Use empty on a variety of different expressions:

// A variable that does not exist
if(empty($x)) {
  echo '$x does not exist<br>';

// An empty integer
if(empty(0)) {
  echo '0 is empty<br>';

// An empty float
if(empty(0.0)) {
  echo '0.0 is empty<br>';

// An empty string
if(empty("")) {
  echo '"" is an empty string<br>';

// null
if(empty(null)) {
  echo 'null is empty<br>';

// A value that is not empty
if(empty('A')) {
  echo '"A" is empty<br>';
} else {
  echo '"A" is not empty<br>';
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❮ PHP Keywords