Functions (Methods) in Java — Revision Notes

Definition

Syntax

returnType methodName(type param) {
    return value;
}

Example

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

    public static void main(String[] args) {
        int result = add(4, 7);
        System.out.println("Sum: " + result);
    }
}

Output

Important Points

• Methods are declared inside a class — there are no free-floating functions in Java.
• static methods belong to the class; instance methods belong to individual objects.
• Java supports method overloading: same name, different parameter lists.
• Java arguments are passed by value, but for objects, the value passed is a reference to the object.

Common Mistakes

• Trying to call a non-static method directly from main without creating an object first.
• Overloading methods that differ only by return type — Java doesn't allow this.
• Confusing "pass by value" for objects with "pass by reference" — Java passes object references by value.

Interview Tip