Given: class Messenger { String msg; Messenger(String msg) {this.msg = msg;} public void writeMsg() { System.out.println(msg); } public void readMsg () { // line n1 } } Messenger m = new Messenger…

Question

Options

• Avoid writeMsg();
• BMessenger.writeMsg();
• CwriteMsg();
• Dm.writeMsg();

• A
  13% (4)
• B
  77% (23)
• C
  7% (2)
• D
  3% (1)

Explanation

There's an error in the listed answer - C is actually correct, not B. Here's the explanation:

Option C (writeMsg();) is correct because readMsg() is an instance method inside the same Messenger class, so it can call writeMsg() directly - this is shorthand for this.writeMsg(), which is always valid within the same class instance.

Why the others are wrong:

• A (void writeMsg();) is a method declaration stub, not a method call - it's a syntax error in this context.
• B (Messenger.writeMsg()) attempts to call an instance method using the class name, which is only valid for static methods. Since writeMsg() is not static, this causes a compile error.
• D (m.writeMsg()) references the variable m, which is declared outside the class in the outer scope - it is not in scope inside readMsg(), causing a compile error.

Memory tip: When calling an instance method from within the same class, you never need a reference - just use the method name directly (the compiler implicitly uses this). Only use ClassName.method() for static methods.

Note: The answer key you were given lists B as correct, but that is a mistake. B would fail to compile. Flag this with your instructor.

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