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UberFoX: /* Remarks */

2013-10-03T13:08:05Z

Remarks

← Older revision		Revision as of 13:08, 3 October 2013
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	=== Remarks ===		=== Remarks ===

−	A classes __IsSet() function will be called when IsSet() is used on a class.	+	A classes __IsSet() function will be called when IsSet() is used on a class if there is no __IsSet() function IsSet() will return true for the class otherwise it will use the return value of __IsSet() and check if that's true.

	=== Example ===		=== Example ===

UberFoX: Created page with "

 IsSet( $variable )

=== Description === Determine if a variable is set and is not NULL If a variable has been unset with Unset(), it will no longer be set. IsSet(..."

2013-10-03T01:59:42Z

Created page with "<pre> IsSet( $variable ) </pre> === Description === Determine if a variable is set and is not NULL If a variable has been unset with Unset(), it will no longer be set. IsSet(..."

New page

<pre>
IsSet( $variable )
</pre>

=== Description ===

Determine if a variable is set and is not NULL

If a variable has been unset with Unset(), it will no longer be set.

IsSet() will return FALSE if testing a variable that has been set to NULL.

Also note that a NULL byte ("\0") is not equivalent to the Sputnik SV NULL type.

If multiple parameters are supplied then IsSet() will return TRUE only if all of the parameters are set.

Evaluation goes from left to right and stops as soon as an unset variable is encountered.

=== Parameters ===

==== $variable ====

The variable to be checked.

You may add as many variables to be checked as you wish separate them with ,

=== Return Value ===

Success - Returns true.

Failure - Returns false.

=== Remarks ===

A classes __IsSet() function will be called when IsSet() is used on a class.

=== Example ===

A few examples

<syntaxhighlight lang="sputnik">
$var = '';

// This will evaluate to TRUE so the text will be printed.
if (isset($var))
{
echo "This var is set so I will print.\n";
}

// In the next examples we'll use var_dump to output
// the return value of isset().

$a = "test";
$b = "anothertest";

say isset($a); // TRUE
say isset($a, $b); // TRUE

unset ($a);

say isset($a); // FALSE
say isset($a, $b); // FALSE

$foo = NULL;
say isset($foo); // FALSE
</syntaxhighlight>

This also work for elements in arrays:

<syntaxhighlight lang="sputnik">
$a = array ('test' => 1, 'hello' => NULL, 'pie' => array('a' => 'apple'));

say isset($a['test']); // TRUE
say isset($a['foo']); // FALSE
say isset($a['hello']); // FALSE

// The key 'hello' equals NULL so is considered unset
// If you want to check for NULL key values then try:
say IsKeySet($a, 'hello'); // TRUE

// Checking deeper array values
say isset($a['pie']['a']); // TRUE
say isset($a['pie']['b']); // FALSE
say isset($a['cake']['a']['b']); // FALSE
</syntaxhighlight>

Yet another example

<syntaxhighlight lang="sputnik">
IsSet($a) # Check if $a is set
IsSet($a['Test']) # Check if $a (as array) index 'Test' is set
IsSet($a['Test']['Cat']) # Check if $a (as array) index 'Test' (as array) index 'Cat' is set
</syntaxhighlight>

[[Category:Core Function]]

Core Function IsSet - Revision history

UberFoX: 1 revision

UberFoX: 1 revision

UberFoX: /* Remarks */

UberFoX: Created page with "
IsSet( $variable )
=== Description === Determine if a variable is set and is not NULL If a variable has been unset with Unset(), it will no longer be set. IsSet(..."