Local Scope
We’ll start backwards with the local scope. Local scope refers the the current base scope of any written code. For any code written directly in a timeline, the local scope is the scope of that timeline. Since most of your code is written directly on your timelines, this probably applies to much of your script – at least that which is not within the definition of functions.

A code block for a function can access _global and current timeline variables directly simply by using their name. Functions have access to those scopes in that manner (and everything does for _global values). For instance, if you define a variable and a function in the same timeline, the function, as long as its called after the definition of the variable, will be able to access the value of that variable within its function call.

timelineValue = "timeline variable";

accessTimelineVariable = function(){

trace(timelineValue); // traces "timeline variable"

};

accessTimelineVariable();

Each function call itself, however, also has its own local scope. This is a scope specific to each call as if the call itself was an object. Variables within this scope are accessed just as timeline variables are only variables local to the function call are not accessible in the timeline outside of that function. You can define variables in this scope using the var keyword. If var is not used in a function call in defining variables, the variables will be defined in the timeline itself and will actually be accessible outside of that function.

defineVariables = function(){

var local = "local value";

timeline = "timeline value";

 

trace(local); // traces "local value"

trace(timeline); // traces "timeline value"

};

 

defineVariables();
 

trace(local); // traces undefined
 

trace(timeline); // traces "timeline value"

When parameters are passed into a function call, those values are assigned as arguments that exist in the local scope of that call.

traceArguments = function(argA, argB){

trace(argA); // traces 1

trace(argB); // traces 2

};

traceArguments(1, 2);

Its this local scope that you would want to define variables that are specific to each function call, such as function arguments, that are to be used only in that code that are not to interfere with anything else. Be sure to remember var or those variables will be set in the timeline and could potentially disrupt your script and other actions or values within your timeline.

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