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Question 1

What does the void keyword indicate in a method definition?

  • A) The method returns an integer value. Incorrect: void means no return type, not integer.

  • B) The method does not return any value. Correct: void means the method does not return any value.

  • C) The method returns a boolean value. Incorrect: void means no return type, not boolean【5†source】.

Question 2

What is the correct way to call a method named sayHelloWorldTwice?

  • A) sayHelloWorldTwice. Incorrect: Method calls in Java require parentheses, even if no arguments are being passed.

  • B) sayHelloWorldTwice(). Correct: This is the correct syntax to call a method in Java.

  • C) sayHelloWorldTwice(); Incorrect: While this is valid in a statement context, it's not the correct way to just refer to a method call【6†source】.

Question 3

Which of the following statements is true about method definitions and method calls?

  • A) Defining a method automatically executes its statement body. Incorrect: Defining a method does not execute its body.

  • B) Defining a method and invoking it are the same thing. Incorrect: Defining a method is different from invoking it.

  • C) Defining and invoking methods are two different steps. Correct: In Java, a method must first be defined and then invoked for the code in the method to execute【7†source】.

Question 4

What is the correct syntax for defining a method that prints "Hello World"?

  • A) void printHelloWorld() { System.out.println("Hello World"); }. Correct: This is the correct syntax for defining a method in Java.

  • B) printHelloWorld() { System.out.println("Hello World"); }. Incorrect: Java methods require a return type, in this case, 'void' is missing.

  • C) void printHelloWorld { System.out.println("Hello World"); }. Incorrect: Parentheses are required after the method name to indicate it's a method【8†source】.

Question 5

Which of these method names follows the same naming rules as variable names?

  • A) 1stMethod. Incorrect: Variable names cannot start with a number.

  • B) method_one. Correct: This follows the Java naming rules, can contain alphanumeric characters and underscores, and cannot start with a number.

  • C) first-Method. Incorrect: Hyphens are not allowed in Java method names【9†source】.

Question 6

Which command lists the methods defined in the current JShell session?

  • A) /methods. Correct: This command lists the methods defined in the current JShell session.

  • B) /list. Incorrect: This command lists the statements entered during the current JShell session.

  • C) /edit. Incorrect: This command opens a method definition in a separate editor window【10†source】.

Question 7

What does the /edit command do in JShell?

  • A) Lists the code of the specified method. Incorrect: This is not the function of the /edit command.

  • B) Allows you to modify the method definition in a separate editor window. Correct: The /edit command opens the definition of a method in a separate editor window for modification.

  • C) Saves the session method definitions to a file. ``Incorrect: This is the functionality of the /save command, not /edit`【11†source】.

Question 8

What is the correct syntax for defining a method with an argument?

  • A) void methodName(ArgType argName) { method-body }. Correct: This is the correct syntax to define a method with arguments in Java.

  • B) methodName(ArgType argName) { method-body }. Incorrect: Java methods require a return type.

  • C) methodName(ArgType argName) { method-body; }. Incorrect: The semicolon at the end is not necessary and the return type is missing【12†source】.

Question 9

Which method definition correctly prints all integers from 1 to n (inclusive), where n is an argument?

  • A)

void printNumbers(int n) {

for (int i = 1; i <= n; i++) {

System.out.println(i);

}

}

Correct: This method correctly prints all integers from 1 to n【13†source】.

Question 10

What would happen if you try to call the method sayHelloWorld with a string argument, when the method is defined to accept an integer argument?

  • A) The program will compile and run without any errors. Incorrect: The method call will fail to compile due to incompatible types.

  • B) The program will throw a runtime error. Incorrect: The error will occur at compile time, not runtime.

  • C) The program will fail to compile due to incompatible types. Correct: Java is statically-typed, meaning the type of each variable and expression is checked at compile time【14†source】.

Question 11

What is method overloading in Java?

  • A) The ability to have multiple methods with the same name in a class, but with different types of arguments. Correct: Method overloading allows multiple methods with the same name but different parameter lists in a class.
  • B) The ability to have multiple methods with the same name and the same types of arguments in a class. Incorrect: Methods with the same name and argument types are considered duplicates and will result in a compilation error.
  • C) The ability to have a single method with an arbitrary number of arguments. Incorrect: This describes varargs, not method overloading【16†source】.

Question 12

Consider the following two method definitions:

void printName(String firstName, String lastName) {
  System.out.println(firstName + " " + lastName);
}

void printName(String firstName, String middleName, String lastName) {
  System.out.println(firstName + " " + middleName + " " + lastName);
}

Which of the following statements are true?

  • A) The two methods are overloaded methods. Correct: These methods have the same name but different parameters, which is a feature of method overloading.
  • B) The two methods have the same name and different number of arguments. Correct: These methods indeed have the same name but different number of arguments.
  • C) The two methods have the same name and the same types of arguments. Incorrect: While they have the same types of arguments, the number of arguments is different, so this statement is false【17†source】.

Question 13

What will the following code snippet output?

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

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

sum(1, 2);
sum(1, 2, 3);
  • A) The output will be 3 6. Correct: The first call to sum uses the two-parameter version, while the second call uses the three-parameter version.
  • B) The output will be 3 5. Incorrect: The second call to sum(1,2,3) would yield 6, not 5.
  • C) The code will not compile due to method overloading. Incorrect: Method overloading is a valid concept in Java, and this code would compile and run correctly【18†source】.

Question 14

Which of the following statements is true about methods with multiple arguments in Java?

  • A) A method can only accept up to 2 arguments. Incorrect: A method in Java can accept any number of arguments.
  • B) A method can accept any number of arguments, but they must be of the same type. Incorrect: A method can accept arguments of different types.
  • C) A method can accept any number of arguments, and they can be of different types. Correct: In Java, a method can accept any number of arguments, and these arguments can be of different types【19†source】.

Question 15

What is the main purpose of method overloading in Java?

  • A) To reduce code duplication by allowing methods with the same name but different arguments. Correct: One of the benefits of method overloading is that it allows the same method name to be used with different parameters.
  • B) To allow a method to return different types of values based on the input arguments. Incorrect: Method overloading does not affect the return type of a method.
  • C) To create multiple methods with the same name and the same number of arguments, but with different implementation. Incorrect: The methods would need to have different parameter lists to be considered overloaded【20†source】.

Question 16

What is the purpose of a return statement in a method?

  • A) To end the execution of the method. Incorrect: While a return statement does end the execution of a method, its main purpose is to return the result of a computation to the calling code.
  • B) To return the result of a computation to the calling code. Correct: The primary purpose of the return statement in a method is to return the result of a computation to the calling code.
  • C) To print the output of the method. Incorrect: Printing the output is the job of the System.out.println() method, not the return statement【21†source】.

Question 17

What is the benefit of using a return mechanism in a method?

  • A) It allows the method to print the result of the computation. Incorrect: Printing is not the job of the return statement, rather it returns the result to the calling code.
  • B) It enables sharing computed results with other code and methods, and improves breaking down a problem into sub-problems. Correct: The return mechanism enables the reuse of computed results in other parts of the code.
  • C) It simplifies the syntax of the method. Incorrect: While the use of return can make a method more readable, it does not necessarily simplify the syntax【22†source】.