dictionary object
This method will delete all key and value pairs currently present in the dictionary.
bool delete_all()
Parameters:
None.
Return value:
true on success, false on failure.
Remarks:
None.
Example:

    // Set some values, then delete them all.

    dictionary game_board; // Declare our dictionary.

    void main()
    {
    // Set our values.
    game_board.set("1", 2); // Sets the value 2 to a key called 1.
    game_board.set("2", 4); // Sets the value 4 to a key called 2.
    game_board.delete_all(); // Delete all the values.
    }