Determine whether a variable is empty

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- PHP Manual
- Variable handling Functions
- Determine whether a variable is empty

# empty

(PHP 4, PHP 5, PHP 7, PHP 8)

empty — Determine whether a variable is empty

### Description

empty(mixed `$var`): bool

Determine whether a variable is considered to be empty. A variable is considered empty if it does not exist or if its value equals `false`. empty() does not generate a warning if the variable does not exist.

### Parameters

`var`

  Variable to be checked

  No warning is generated if the variable does not exist. That means empty() is essentially the concise equivalent to !isset($var) || $var == false.

### Return Values

Returns `true` if `var` does not exist or has a value that is empty or equal to zero, aka falsey, see conversion to boolean. Otherwise returns `false`.

### Examples

Example #1 A simple empty() / isset() comparison.

    <?php$var = 0;// Evaluates to true because $var is emptyif (empty($var)) {    echo '$var is either 0, empty, or not set at all';}// Evaluates as true because $var is setif (isset($var)) {    echo '$var is set even though it is empty';}?>

Example #2 empty() on String Offsets

    <?php$expected_array_got_string = 'somestring';var_dump(empty($expected_array_got_string['some_key']));var_dump(empty($expected_array_got_string[0]));var_dump(empty($expected_array_got_string['0']));var_dump(empty($expected_array_got_string[0.5]));var_dump(empty($expected_array_got_string['0.5']));var_dump(empty($expected_array_got_string['0 Mostel']));?>

The above example will output:

    bool(true)
    bool(false)
    bool(false)
    bool(false)
    bool(true)
    bool(true)

### Notes

> Note: Because this is a language construct and not a function, it cannot be called using variable functions, or named arguments.

> Note:

> When using empty() on inaccessible object properties, the __isset() overloading method will be called, if declared.

### See Also

- isset() - Determine if a variable is declared and is different than null
- __isset()
- unset() - Unset a given variable
- array_key_exists() - Checks if the given key or index exists in the array
- count() - Counts all elements in an array or in a Countable object
- strlen() - Get string length
- The type comparison tables