Changes

Although the variables and arguments in the first example (where the variables are not passed by reference) share the same name it is important to note that they are still separate, independent variables. In other words, modifying ''$var1'' within the function does not change the value assigned to the ''$var1'' variable declared outside the function. The ability to have two variables with the same name in this context is the result of something called ''variable scope'', a a topic that will be covered later in this chapter.