What restriction applies to method overloading in Java?

• A. Two methods must have the same return type.
• B. Two methods cannot have the same argument list.
• C. All overloaded methods must be static.
• D. Overloaded methods can only differ by name.

Answer: (B)

In Java, method overloading allows multiple methods in the same class to have the same name but differ in their parameter lists. The key restriction for method overloading is that two methods must not have the same argument list, which encompasses both the number and type of parameters. This means that if two methods have identical parameter types and counts, the Java compiler will not be able to differentiate between them during a method call, leading to ambiguity.

For example, you could have one method that takes an int and another that takes a String, but you wouldn’t be able to define two methods that both take an int as a parameter, even if they returned different types. Thus, the uniqueness of the method signature, which consists of the method name and its parameter list, is crucial for the compiler to differentiate between overloaded methods.

This understanding is pivotal as it affects how developers create and use methods in Java, ensuring that the method signatures are distinct enough for proper invocation by the calling code.