PHP empty function

empty

(PHP 3, PHP 4, PHP 5)

empty -- Determine whether a variable is emptyDescriptionbool empty ( mixed var )

Determine whether a variable is considered to be empty.

Parameters

var

Variable to be checked

Note:
empty() only checks variables as anything else will
result in a parse error. In other words, the following will not work:
empty(trim($name)).

empty() is the opposite of
(boolean) var,
except that no warning is generated when the variable is not set.

Return Values

Returns FALSE if var has a non-empty
and non-zero value.

The following things are considered to be empty:

"" (an empty string)0 (0 as an integer)"0" (0 as a string)NULLFALSEarray() (an empty array)var $var; (a variable declared, but without a value in a class)

ChangeLog

VersionDescriptionPHP 5

As of PHP 5, objects with no properties are no longer considered empty.

PHP 4

As of PHP 4, The string value "0" is considered empty.

Examples

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

$var = 0;

// Evaluates to true because $var is empty
if (empty($var)) {
echo '$var is either 0, empty, or not set at all';
}

// Evaluates as true because $var is set
if (isset($var)) {
echo '$var is set even though it is empty';
}

Notes

Note: Because this is a
language construct and not a function, it cannot be called using
variable functions

BRADINO

PHP empty function

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