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previousis_stringprint_rnext
Last updated: Mon, 28 Oct 2002
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isset

(PHP 3, PHP 4 )

isset -- Prüft die Existenz einer Variablen

Beschreibung:

int isset ( mixed var)

Diese Funktion liefert TRUE, wenn die Variable oder das Array-Element var existiert, sonst FALSE.

Wird eine Variable oder ein Array-Element mit unset() freigegeben, so liefert isset() anschließend ebenfalls FALSE. 

echo isset ($a); // false
$a = "test";
echo isset ($a); // true
unset ($a);
echo isset ($a); // false

Siehe auch empty() und unset().

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previousis_stringprint_rnext
Last updated: Mon, 28 Oct 2002
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Last updated: Thu Oct 31 18:34:28 2002 EST