what does Dim do?

[garysenter]

i know i should know this , but what does Dim do/mean? I see a lot of people using it in macros.

 

[NateO]

It declares the name, data type and possibly dimension of local variables, either at a procedural or modular level of scope.

 

[BrianB]

It also reserves a memory space at the beginning of a project (items at the top of the list are found quicker). Only really makes a difference when the variable is used withing a long-running loop.