PHP | empty() Function

The empty() function is an inbuilt function in PHP which is used to check whether a variable is empty or not.

Syntax:

bool empty ( $var )

Parameter: This function accepts a single parameter as shown in above syntax and described below.

• $var: Variable to check whether it is empty or not.

Note: Below version of PHP 5.5, empty() only supports variables, anything other will result in a parse error. The following statement will not work empty(trim($var)). Instead, use trim($name) == false.

Return Value: It returns FALSE when $var exists and has a non-empty, non-zero value. Otherwise it returns TRUE.

These values are considered to be as an empty value:

• “” (an empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• “0” (0 as a string)
• NULL
• FALSE
• array() (an empty array)

Below program illustrate the empty() function in PHP:

<?php
// PHP code to demonstrate working of empty() function
$var1 = 0;
$var2 = 0.0;
$var3 = "0";
$var4 = NULL;
$var5 = false;
$var6 = array();
$var7 = "";

// for value 0 as integer
empty($var1) ? print_r("True\n") : print_r("False\n");

// for value 0.0 as float
empty($var2) ? print_r("True\n") : print_r("False\n");

// for value 0 as string
empty($var3) ? print_r("True\n") : print_r("False\n");

// for value Null
empty($var4) ? print_r("True\n") : print_r("False\n");

// for value false
empty($var5) ? print_r("True\n") : print_r("False\n");

// for array
empty($var6) ? print_r("True\n") : print_r("False\n");

// for empty string
empty($var7) ? print_r("True\n") : print_r("False\n");

// for not declare $var8
empty($var8) ? print_r("True\n") : print_r("False\n");

?>

Output:

True
True
True
True
True
True
True
True

Reference : http://php.net/manual/en/function.empty.php