Java return Keyword
Usage and Examples

return Keyword in Java

The return keyword in Java is used to exit from a method and optionally send a value back to the caller. It plays a central role in method communication, allowing you to write reusable and logical code blocks.

Where is return Used?

The return keyword can be used in two scenarios:

• Returning a value from a method that has a return type.
• Exiting a method early when the return type is void.

Basic Syntax of return

return;             // Used in void methods
return expression;  // Used to return a value from non-void methods

Example 1: Using return to Exit a void Method

public class Demo {
  public static void greet(String name) {
    if (name == null) {
      System.out.println("No name provided.");
      return; // exits the method early
    }
    System.out.println("Hello, " + name);
  }

  public static void main(String[] args) {
    greet(null);
    greet("Alice");
  }
}

No name provided.
Hello, Alice

Explanation

When name is null, the return statement exits the method immediately, skipping the greeting message.

Example 2: Returning a Value from a Method

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

  public static void main(String[] args) {
    int result = add(10, 20);
    System.out.println("Sum: " + result);
  }
}

Sum: 30

Explanation

The method add returns the sum of two integers using the return keyword. The value is stored in the result variable in main and printed.

Example 3: Return with Conditional Logic

public class GradeChecker {
  public static String getGrade(int score) {
    if (score >= 90) return "A";
    if (score >= 80) return "B";
    if (score >= 70) return "C";
    return "F";
  }

  public static void main(String[] args) {
    System.out.println(getGrade(85));
    System.out.println(getGrade(65));
  }
}

B
F

Explanation

This shows how return is used in multiple decision paths. The method exits immediately once a matching condition is found.

Important Rules about return

• If a method has a return type (like int, String, etc.), it must return a value.
• If the method is void, you can use return; to exit early, but it’s optional.
• Code written after a return statement in a method is unreachable and will cause a compile-time error.

Example 4: Error - Missing Return Statement

public class Demo {
  public static int getNumber(boolean flag) {
    if (flag) {
      return 10;
    }
    // Compile-time error: missing return statement
  }
}

Best Practices

• Use return early to avoid unnecessary nesting of logic.
• Ensure every code path in a non-void method returns a value.
• Use meaningful return values to simplify testing and reusability.

When Not to Use return

You should avoid using return inside deeply nested blocks unless it improves readability. In large methods, excessive returns may reduce clarity.

Summary

The return keyword in Java serves as the bridge between a method’s logic and its output. Whether you’re cutting short a method’s execution or sending back computed results, mastering return helps write effective, modular Java code.

Common Interview Questions

• What does the return keyword do in a void method?
• Can a method contain multiple return statements?
• What happens if a non-void method does not return anything?