CHECKTYPE
Syntax CHECKTYPE object type
 
Explanation CHECKTYPE checks a Logo name for being an object of a certain type. Since a Logo name may be a bitmap, a button, a turtle, or any of the other built-in types, its properties vary from type to type. If the object given as its first input does not match the type given as the second input of CHECKTYPE, Logo throws a runtime error.

A Logo name may have more than one type. The Listener window is, for example, a WINDOW as well as a LISTENER.

CHECKTYPE is handy for ensuring that a Logo name has a certain built-in property.

See also IS.A.
 

Examples CHECKTYPE "LISTENER "WINDOW
CHECKTYPE "LISTENER "TURTLE
LISTENER is not a WINDOW

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