Method overloading: deeper practice

1 Learn

Overloaded methods must differ in their parameter list: number, types or order of parameters.

Changing only the return type is NOT enough — Java would not know which one to call.

Overloading is common: System.out.println itself is overloaded for int, double, String and more.

Want more detail? Open the full lesson

2 See the Code

Java

public class Printer {
    static void show(int x) { System.out.println("int: " + x); }
    static void show(double x) { System.out.println("double: " + x); }
    static void show(String s) { System.out.println("text: " + s); }
    static void show(String s, int times) {
        for (int i = 0; i < times; i++) System.out.println(s);
    }

    public static void main(String[] args) {
        show(5);
        show(2.5);
        show("hi");
        show("ok", 2);
    }
}

Java picks the version whose parameters match the arguments.
show("ok", 2) matches the two-parameter version.

Output

int: 5
double: 2.5
text: hi
ok
ok

3 Practice

Write overloaded max(int, int), max(int, int, int) and max(double, double).

Try it in your own Java setup or write it in the Practice Notebook.

4 Quick Check

1. Which pair is a valid overload?
2. Overloading is decided at...

Step 5

Answer and check the Quick Check above to unlock this.

Day 23