The empty() function is an inbuilt function in PHP that is used to check whether a variable is empty or not.
These values are considered to be empty values:
- “” ( 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)
Example: Below example illustrate the empty() function in PHP.
PHP
<?php // PHP code to demonstrate the 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");?> |
True True True True True True True True
isset() Function: The isset() function is an inbuilt function in PHP that is used to determine if the variable is declared and its value is not equal to NULL.
Parameters: This function accepts one or more parameters as mentioned above and described below.
- $var: It contains the variable which needs to check.
- $…: It contains the list of other variables.
Return Value: It returns TRUE if var exists and its value is not equal to NULL and FALSE otherwise.
Example 2: Below examples illustrate the isset() function in PHP:
PHP
<?php$str = "neveropen";// Check value of variable is set or notif(isset($str)) { echo "Value of variable is set";}else { echo "Value of variable is not set";}$arr = array();// Check value of variable is set or notif( !isset($arr[0]) ) { echo "\nArray is Empty";}else { echo "\nArray is not empty";}?> |
Value of variable is set Array is Empty
PHP program using both isset() and empty() functions:
PHP
<?php// PHP function to demonstrate// isset() and !empty() function// initialize a variable$num = '0';// Check isset() functionif( isset ( $num ) ) { print_r( $num . " is set with isset function");}// Display new lineecho "\n";// Initialize a variable$num = 1;// Check the !empty() functionif( !empty ( $num ) ) { print_r($num . " is set with !empty function");}?> |
Output:
0 is set with isset function 1 is set with !empty function
Difference between isset() and empty() function:
|
isset() Function |
empty() Function |
| The isset() function is an inbuilt function in PHP that is used to determine if the variable is declared and its value is not equal to NULL. | The empty() function is an inbuilt function in PHP that is used to check whether a variable is empty or not. |
| The isset() function will generate a warning or e-notice when the variable does not exists. | The empty() function will not generate any warning or e-notice when the variable does not exists. |
