free

OpenTuring

freestatement

Syntax   A freeStatement is:

 free [ collectionOrClassId, ] pointerVariableReference

Description   A free statement destroys (deallocates) an element that has been allocated by a new statement.

Example   Using a collection, declare a list of records and allocate one of these records. Then deallocate the record.

        var list : collection of
            record
                contents : string ( 10 )
                next : pointer to list
                            % Short form: next : ^ list
            end record
        var first : pointer to list % Short form: var next : ^ list
        new list, first
                % Allocate an element of list; place its location in first
                % Short form: new first
        
        free list, first    % Deallocate the element of list located by first
                    % Short form: free first

Details   The free statement sets the pointer variable to the nil value. See the new statement for examples of allocating elements of classes and values of types. It the pointer locates a type, the collectionOrClassId in the free statement must be omitted.

An imported class can have one of its objects destroyed (by the free statement) only if the class is imported var.

The collectionOrClassId is optional in the free statement.

See also   class and collection declarations, the pointer type, the new statement and the nil value.