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Local Variables

About this time, you might be wondering how we can use the same variable i in both printMultiples and printMultTable. Didn't I say that you can only declare a variable once? And doesn't it cause problems when one of the methods changes the value of the variable?

The answer to both questions is "no," because the i in printMultiples and the i in printMultTable are not the same variable. They have the same name, but they do not refer to the same storage location, and changing the value of one of them has no effect on the other.

Variables that are declared inside a method definition are called local variables because they are local to their own methods. You cannot access a local variable from outside its "home" method, and you are free to have multiple variables with the same name, as long as they are not in the same method.

It is often a good idea to use different variable names in different methods, to avoid confusion, but there are good reasons to reuse names. For example, it is common to use the names i, j and k as loop variables. If you avoid using them in one method just because you used them somewhere else, you will probably make the program harder to read.

Last Update: 2011-01-24