Nate Brunelle Today: Functions again, Scope CS1110 Nate Brunelle Today: Functions again, Scope

Questions?

Last Time Functions

Visualizing Programs http://www.pythontutor.com/visualize.html

Scope Scope- The area where a variable has meaning Usually: variable is in scope when it is created onward. Functions: variable is in scope only in the function in which it is defined

What happens when you invoke a function? Create memory for the function Copy argument values into parameter names Do what the function says Know what to return Remove the memory for the function

Which variable v is in scope? If the variable v is available in the local scope, use that one If the variable v is not available in the local scope, use the variable v available in the global scope If a function ever will have the local variable v, you can only use that variable v

Global variables Allow you to have something “remembered” from one run of a function to another.