Unit 2 · Java Fundamentals · 9 min

Methods

A method is a named block of code that does one job. You write it once and call it whenever you need it.

Why this matters

Methods stop repetition, make programs readable, and are the direct stepping stone to classes and objects.

Real-life analogy

A method is like a kitchen appliance. You put ingredients in (parameters), it does its job, and it hands you a result (return value).

Syntax

returnType methodName(parameters) {
    // body
    return value;   // not needed when returnType is void
}

Example

Java

public class Calc {

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

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

    public static void main(String[] args) {
        int sum = add(12, 8);
        System.out.println("Sum = " + sum);
        greet("Ananya Rao");
    }
}

Output

Sum = 20
Hello, Ananya Rao!

Step by step

1`static int add(int a, int b)` declares a method that takes two ints and returns an int.
2`return a + b;` sends the answer back to whoever called the method.
3`void greet(String name)` returns nothing; it only prints.
4`add(12, 8)` is the call. 12 and 8 are arguments; a and b are parameters.
5Methods are marked static here so main can call them without creating an object.

Key points

Parameters are inputs, return value is the output
void means the method returns nothing
A method should ideally do one clear job
Calling a method runs its body and then comes back to where you were

Common mistakes

Forgetting to return a value in a non-void method
Calling a non-static method directly from main without an object
Passing arguments in the wrong order

Try it yourself

Write a method isEven(int n) that returns true or false.
Write a method that returns the largest of three numbers.

Open the practice notebook