PHP - is_null

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Metóda - is_null

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

Determines whether a given variable is null.

Procedurálne

• function is_null (mixed $var) : bool

Parametre

Názov	Dátový typ	Predvolená hodnota	Popis
$var	mixed		The variable being checked.

Mávratovej hodnoty

Vracia: bool

If the given variable is null, then returns true, returns `false `otherwise.

Príklady

<?php
echo is_null(null) ? "null is null.\n" : "null is not null.\n";
echo is_null(array()) ? "array() is null.\n" : "array() is not null.\n";
echo is_null(42) ? "42 is null.\n" : "42 is not null.\n";
echo is_null("hi") ? "'hi is null.\n" : "'hi is not null.\n";