Explaining varargs

Consider the following situation: you want to call a method, m1, but the number of arguments may vary. Do you overload the method with each version of the method taking in one extra parameter? For example, assuming the argument types are of the String type, do you overload m1 when each new version takes in an extra String parameter? In this case, you would have to code m1(String), m1(String, String), m1(String, String, String), and so forth. This is not scalable.

This is where varargs comes in. varargs is a very flexible language feature in Java, specifically provided for this use case. The syntax is that the type name is followed by an ellipsis (three dots). Figure 7.10 shows varargs in action:

Figure 7.10 – varargs example

In this figure, on line 10, m1(int… ) defines a method signature for the m1 method, defining 0 or more int parameters. This is quite different from String[] defined on line 4 for main. In effect...