Symbols are reusable items that can be simple graphics, animations, buttons or text.  They are stored in the library.

An instance is created from a symbol and when it is put onto the stage it looks identical to the symbol from which it was created.

Although instances look just like the original symbol they are not really objects themselves, just references to the symbol.  That way they take up much less file space, so the movie file can be kept very small. 

Instances don't have to look exactly like the symbol they were created from.  They can be a different colour or size.  The example below shows several instances of the same symbol.  They have just had size, colour and orientation adjusted.

There are several different types of symbol that you can use:

The Library

When you create a symbol, it is put into the library.  To view the library, click on the menu bar: Window > Library

The library is a management system for reusable items in your movies.  You should create folders for storing your symbols.

 

 

Adding Symbols to the Library

Creating Graphics

If you are creating a graphic symbol, you can just draw your object on the stage in the usual way, then right click on it and select Convert to Symbol.  You should give it an appropriate name so that you can locate it easily later on. Select Graphic as the type. It will appear immediately in the library. 

Creating Buttons and Movie Clips

Buttons and movie clips each need more than one frame, so it is best to create a new symbol from scratch in the symbol editor.  From the menus choose Insert > New Symbol, or in the library, click the New Symbol icon on the bottom left

You will then enter Symbol Editing Mode.  This is a special symbol editor that you use to create and edit symbols. 

 
It is easy to become confused between symbol editing mode and the main stage, as the two can look very similar at times.
 
When you are in symbol editing mode, at the top left of the stage you can see the name of the symbol you are editing highlighted.
To return to the stage, click the scene editing button at the top right of the editor and select your scene.
   

Importing

You can import sounds, movies, images etc to the library by choosing from the menus File > Import to Library.  Your file will then appear in the library for you to use in your movies.

Editing Symbols and Instances

If you want to edit a symbol while you can still see it on the stage, right click on it and choose Edit in Place.  The other objects on the stage are then visible, but greyed out.

You can edit an individual instance of a symbol by changing its brightness, tint and transparency.  Select the instance by clicking on it, then make the changes in the Property inspector.  An instance can also be reshaped and resized by using the Free Transform tool.

When you make changes in symbol editing mode, these changes will apply to all instances of the symbol on the stage.

If an instance of a symbol is deleted from the stage, the symbol itself will still remain in the library.

But if you delete a symbol from the library, all instances of it will be deleted from the stage.

 

Movie Clips

Movie clips are symbols that are animations in themselves.  They have their own timeline and once created appear in the library.  This is useful if you have a particular animation that you want to use several times. 

From the menus, select Insert > New Symbol

Name the symbol and select Movie Clip as the behaviour.

Even though you are in the symbol editor you can now create the animation just as you would on the stage.  The only difference is that when you are finished the movie clip appears in the library.