Java · Theory

Methods in Java

Theory

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Methods in Java

A method is a reusable block that does one job. Parts: return type, name, parameters, body. void means do the work and return nothing. int square(int n) returns a value.

Call it on an object: s.study(); or on the class if it is static: Math.max(2, 5). Keep methods small — one clear responsibility. Forgetting return in a non-void method is a compile error.

In an interview, write square(int n) live and explain each word of the signature.

Let's take this on the board with one tiny Main class — no extra files. Methods in Java — output: 25. square(5) is 5*5. Change to square(6) in your head — 36. Start from main, go line by line, and stop at each print. That output is the proof for Methods.

Exam tip

Explain signature: return type + name + params. Write square(int n).

Example

public class Main {
  static int square(int n) {
    return n * n;
  }

  public static void main(String[] args) {
    System.out.println(square(5));
  }
}

Methods in Java — output: 25. square(5) is 5*5. Change to square(6) in your head — 36.

Short notes

DefA method is a reusable block that does one job.
RuleSignature = return type + name + parameters.
Remembervoid returns nothing. Non-void must return a value.
Useobject.method() or Class.staticMethod().

Java · Theory

Methods in Java

← All stacks

Theory

29/270

Methods in Java

A method is a reusable block that does one job. Parts: return type, name, parameters, body. void means do the work and return nothing. int square(int n) returns a value.

Call it on an object: s.study(); or on the class if it is static: Math.max(2, 5). Keep methods small — one clear responsibility. Forgetting return in a non-void method is a compile error.

In an interview, write square(int n) live and explain each word of the signature.

Exam tip

Explain signature: return type + name + params. Write square(int n).

Example

public class Main {
  static int square(int n) {
    return n * n;
  }

  public static void main(String[] args) {
    System.out.println(square(5));
  }
}

Methods in Java — output: 25. square(5) is 5*5. Change to square(6) in your head — 36.

Short notes

DefA method is a reusable block that does one job.
RuleSignature = return type + name + parameters.
Remembervoid returns nothing. Non-void must return a value.
Useobject.method() or Class.staticMethod().

Methods in Java

Example

Short notes

Questions

Methods in Java

Example

Short notes

Questions