instanceof - MethodScript

== instanceof ==

Checks to see if the value is, extends, or implements the given type. Keyword usage is preferred: @value instanceof int. The opposite operation is @value notinstanceof int.

=== Vital Info === {| style="width: 40%;" cellspacing="1" cellpadding="1" border="1" class="wikitable" |- ! scope="col" width="20%" | ! scope="col" width="80%" | |- ! scope="row" | Name | instanceof |- ! scope="row" | Returns | boolean |- ! scope="row" | Usages | value, type |- ! scope="row" | Throws | |- ! scope="row" | Since | 3.3.1 |- ! scope="row" | Restricted |

|- ! scope="row" | Optimizations | [[../../Optimizer#OPTIMIZE_DYNAMIC|OPTIMIZE_DYNAMIC]] |}

Null is a special value, while any type may be assigned null, it does not extend any type, and therefore "null instanceof AnyType" will always return false. Likewise, other than null, all values extend "mixed", and therefore "anyNonNullValue instanceof mixed" will always return true. There is no (single) functional equivalent to the notinstanceof keyword. @value notinstanceof int simply compiles to not(instanceof(@value, int)).

=== Usages ===

instanceof(value, type)

=== Examples === ====Example 1==== Basic usage Given the following code:

mixed @a = 5; // Actually an int
msg(@a instanceof int); // true
msg(@a instanceof string); // false
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1   {{object|mixed}} @a = 5; // Actually an int
2   
3   {{function|msg}}(@a {{keyword|instanceof}} {{object|int}}); // true
4   
5   {{function|msg}}(@a {{keyword|instanceof}} {{object|string}}); // false

The output would be:

true
false

====Example 2==== Functional usage Given the following code:

instanceof(5, int)
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1   {{keyword|instanceof}}(5, {{object|int}})

The output would be:

:true

====Example 3==== Inverted usage Given the following code:

mixed @a = 5;
msg(@a notinstanceof int); // false
msg(@a notinstanceof string); // true
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1   {{object|mixed}} @a = 5;
2   {{function|msg}}(@a {{keyword|notinstanceof}} {{object|int}}); // false
3   
4   {{function|msg}}(@a {{keyword|notinstanceof}} {{object|string}}); // true

The output would be:

false
true

====Example 4==== Inverted functional usage Given the following code:

!instanceof(5, int)
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1   !{{keyword|instanceof}}(5, {{object|int}})

The output would be:

:false

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