The Scope of a Variable

What is a variable’s scope?

When we declare a variable, the portion of the program where we can use that variable is called its scope. This portion extends from the declaration itself to the closing brace that encloses the declaration. That is, the closing brace ends the compound statement or method that contains the variable’s declaration.

Example

For example, the figure given below contains the main method that appeared in the previous lesson. The scope of starCounter begins at its declaration and extends to the end of the outer while loop. Thus, starCounter is available for use anywhere within this portion of the program. It would be undefined after the closing brace of the outer while loop, for example. Both rowCounter and sideLength have a scope that begins at their respective declaration and extends to the end of the main method.