Methods in Java

Methods

• Performs a specific task,Improves Readability,Allows code reuse
• Can take Parameters and Return a value
• Can be Static or Instance
• Supports Method Overloading

Basic Syntax

returnType methodName(parameters) {
    // method body
    // code to execute
    return value; // optional
}

Types of Methods in Java
1. Predefined Methods

These are already available in Java libraries.

Example:

System.out.println("Hello");

Here, println() is a predefined method.

2. User-defined Methods

Methods created by the programmer.

Example:

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

- Method Parameters
Methods can accept input values.

void add(int a, int b) {
    System.out.println(a + b);
}

Explanation
a and b are parameters

- Return Type
A method can return a value using return

Example:

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

Usage:
int result = add(5,3);
System.out.println(result);

Output
8

3.Method Without Return Value (void)
If a method does not return anything, we use void.

Example:

void message() {
System.out.println("Welcome");
}

4.Static Methods
Belong to the class,not to the object

class Test {
    static void show() {
        System.out.println("Static Method");
    }

    public static void main(String[] args) {
        show();
    }
}

Hence no object is required

5.Instance Methods
Requires an object to call them

class Test {
    void display() {
        System.out.println("Instance Method");
    }

    public static void main(String[] args) {
        Test t = new Test();
        t.display();
    }
}

6.Method Overloading
Allows multiple methods with the same name but different parameters.

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

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

7.Method can call other methods

void greet(){
    System.out.println("Hello");
}

void welcome(){
    greet();
    System.out.println("Welcome");
}

Types Of Methods

1. Method with No Parameter and No Return Value
No input,does not return anything

class Demo {
    void greet() {
        System.out.println("Hello Priya");
    }

    public static void main(String[] args) {
        Demo d = new Demo();
        d.greet();
    }
}

Output
Hello Priya

Explanation
No Parameter inside ()
No Return Statement
Uses Void

2.Method with Parameter and No Return Value
takes input,does not return anything

class Demo {
    void add(int a, int b) {
        System.out.println(a + b);
    }

    public static void main(String[] args) {
        Demo d = new Demo();
        d.add(5, 3);
    }
}

Output
8

Explanation
Takes parameter a and b
Prints result directly
Uses Void

3.Method with Parameter and Return Value
Takes input and return a value

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

    public static void main(String[] args) {
        Demo d = new Demo();
        int result = d.add(5, 3);
        System.out.println(result);
    }
}

Output
8

Explanation
Takes parameter
Returns result using return

4.Method with No Parameter but Return Value
Takes no input , return value

class Demo {
    int number() {
        return 10;
    }

    public static void main(String[] args) {
        Demo d = new Demo();
        int value = d.number();
        System.out.println(value);
    }
}

Output
10