Methods

So far all our code has been crammed into main. A method is a piece of code we give a name to, write once, and reuse as many times as we want. In fact you've already used one dozens of times: System.out.println is a method

Let's write our own method

public class Main {
    public static void greet(String name) {
        System.out.println("Hello, " + name);
    }

    public static void main(String[] args) {
        greet("Cortez");
        greet("Tommy Vercetti");
        greet("Lance Vance");
    }
}

Output

Hello, Cortez
Hello, Tommy Vercetti
Hello, Lance Vance

We wrote the greeting logic once, but used it three times. Let's break down the line that declares the method

public static void greet(String name)

Each part has a meaning, for now we explain only the essentials

• public: anyone can call this method
• static: for now, just write it. You'll understand it deeply when you study classes and objects
• void: the method does not return anything (it just prints something)
• greet: the name of the method
• (String name): it takes a parameter called name, of type String. Notice the type before the parameter

We must put public static void at the start. Don't worry about why for now, just trust this pattern

A method can also return a value. In that case, instead of void, we write the type of the returned value

public class Main {
    public static int add(int a, int b) {
        return a + b;
    }

    public static void main(String[] args) {
        int result = add(2, 3);
        System.out.println(result);
    }
}

Output 5

The method add takes two ints and returns an int. Inside, we use return to give back the value. As soon as Java hits return, the method exits immediately: anything written after return is dead code

We can also use the result directly inside another expression

public class Main {
    public static int add(int a, int b) {
        return a + b;
    }

    public static void main(String[] args) {
        System.out.println(add(2, 3) * 10);
    }
}

Output 50. Java first computes add(2, 3) = 5, then 5 * 10 = 50, then prints

The return type must match what we actually return

public class Main {
    public static int add(int a, int b) {
        return "hello";   // error
    }
}

The method promises to return an int, but tries to give back a String. Java refuses to compile. This is one of Java's strict but helpful habits: many bugs are caught before the program even runs

A void method just does its job and exits. We can still use return alone (without a value) to exit early

public class Main {
    public static void greet(String name) {
        if (name.length() == 0) {
            return;   // exit early, no greeting for empty names
        }
        System.out.println("Hello, " + name);
    }
}

Mission: Splitting the Loot

After a successful heist, Tommy splits the loot equally among the crew. You want a method that does the math once and that you can reuse for every heist.

Write a method that takes the total loot and the number of crew members and returns each member's share (use integer division; whatever doesn't divide evenly is lost). Then, in main, store the loot in a variable named loot and the crew size in a variable named crew, call the method, and print a line of the form loot / crew = share.

Example

If the loot is 10000 and the crew has 4 members, your program should print

10000 / 4 = 2500