====MAPFILTER====

Filters a [[map|map]] for specific items.

There are two variants of this function that work differently

===Parameters===

^Order^Name^Type^Desc^
|1|original|[[map|map]]|The map to be filtered|
|2|filterkey|[[const|const]]|The name of the map item to be searched for|
|3|filtervalue|[[const|const]]|The value of the map item to allow|

or

^Order^Name^Type^Desc^
|1|original|[[map|map]]|The map to be filtered|
|2|filterkey|[[map|map]]|The filter|

===Returns===

Places an [[map|map]] on the stack.

===Description===

This function filters the map (//original//). 

If using the three-parameter version, any item that does **not** contain the specified //filterkey// and //filtervalue// will be removed.

If using the two-parameter version, any item that does **not** contain each of the map keys and values found in //filterkey// will be removed.

For example, if you had the following map in your stack...

   [ { "name": "alpha",
       "colour": "orange",
       "style": "plain" },
      { "name": "beta",
        "colour":"blue",
        "style":"exotic"} ]
        
 ...then the command **'colour' 'blue' MAPFILTER** will remove 'alpha' from your map, leaving only 'beta'.

===See Also===

[[fRELATED]] \\
[[fMAPSET]]