Question 1

An overloaded method is one that ________.
A) has a different name than another method, but the same parameters
B) has the same name as another method, but different parameters (by number, types or order of the types)
C) has the same name and parameters as a method defined in another class
D) has the same name and parameters, but a different return type as another method

Accepted Answer

An overloaded method is one that has the same name as another method, but different parameters (by number, types, or order of the types). This allows for multiple methods with the same name to perform different tasks based on the input they receive.

Question 2

A Java class can have which of the following methods? 
A. void foo(int a)
B. void foo(int a, int b)
C. void foo(double a)
D. void foo(double a, double b)
E. void foo(int b)
A) All of the above.
B) A, B, D, E.
C) A, B, C, D.
D) A, C, D, E.

Accepted Answer

All of the methods listed are valid for a Java class, but there is no requirement that every class have a method with an int parameter (option A). Therefore, the correct answer must include C. Options B and D both include option A, which is not necessary, while option D leaves out option C, which is valid. Option C includes all valid methods.

Question 3

Which statement below could be used to simulate the outputs of tossing a quarter to get heads or tails? Suppose randomNumbers is a SecureRandom object.
A) randomNumbers.nextInt(7);
B) randomNumbers.nextInt(2);
C) randomNumbers.nextInt(1);
D) randomNumbers.nextInt(25);

Accepted Answer

Since a coin has two sides (heads and tails), the best choice to simulate the output of tossing a quarter would be to generate random integers between 0 and 1 (inclusive). Therefore, option B, randomNumbers.nextInt(2), is the correct choice.

Question 4

Overloaded methods always have the same _________.
A) method name
B) return type
C) number of parameters
D) order of the parameters

Accepted Answer

Overloaded methods must have the same method name but can differ in parameters (type, number, order).

Question 5

Which of these statements best defines scope?
A) Scope refers to the classes that have access to a variable.
B) Scope determines whether a variable's value can be altered.
C) Scope is the portion of a program that can refer to an entity by its simple name.
D) Scope allows the programmer to use a class without using its fully qualified name.

Accepted Answer

Scope refers to the portion of a program where a particular entity, such as a variable or function, can be accessed by its simple name. It is determined by where the entity is defined in the program and the nesting of code blocks. So, option C is the most accurate definition of scope among the given options.

Question 6

The jjava.text package contains classes for manipulating all of the following items except ________.
A) classes
B) numbers
C) strings
D) characters

Accepted Answer

The java.text package contains classes for manipulating strings, numbers, and characters with specific functions such as formatting, parsing, and regular expressions. It does not contain classes for manipulating other classes.

Question 7

Identifiers in Java have ________ and ________ scopes?
A) method, class.
B) class, block.
C) block, statement.
D) statement, file.

Accepted Answer

Identifiers in Java have two scopes - class scope and block scope. Class scope refers to the scope of the identifier within the entire class, whereas block scope refers to the scope of the identifier within a specific block of code (for example, within a method or a loop). Therefore, option B is the correct answer.

Question 8

Which of the following statements is false?
A) The Java API consists of packages.
B) The Java API helps programmers avoid "reinventing the wheel."
C) The Java API consists of import declarations.
D) None of the above.

Accepted Answer

The Java API does not consist of import declarations, but rather it is accessed through import declarations in a Java program. The Java API consists of packages containing classes, interfaces, and other components that can be used in Java programs.

Question 9

Which statement below could be used to simulate the outputs of rolling a six-sided die? Suppose randomNumbers is a SecureRandom object.
A) 1 + randomNumbers.nextInt(6);
B) 1 + randomNumbers.nextInt(2);
C) 6 + randomNumbers.nextInt(1);
D) 3 + randomNumbers.nextInt(3);

Accepted Answer

Option A generates a random integer between 0 (inclusive) and 6 (exclusive), and then adds 1 to shift the range to 1-6, simulating a six-sided die roll. The other options do not produce a range of values suitable for simulating a die roll.

Question 10

A set of named constants that start with the value 0 for the first constant and increment by 1 for each subsequent constant can be declared as a(n) ________.
A) class
B) enum
C) enumeration
D) None of the above.

Accepted Answer

An enum is a set of named constants that start with a default value of 0 for the first constant and increment by 1 for each subsequent constant. Therefore, a set of named constants that start with the value 0 for the first constant and increment by 1 for each subsequent constant can be declared as an enum.

Question 11

Which statement creates a random value from the sequence 2, 5, 8, 11 and 14. Suppose randomNumbers is a SecureRandom object.
A) 2 + 5 * randomNumbers.nextInt(3);
B) 3 + 2 * randomNumbers.nextInt(5);
C) 5 + 3 * randomNumbers.nextInt(2);
D) 2 + 3 * randomNumbers.nextInt(5);

Accepted Answer

The correct choice is D) 2 + 3 * randomNumbers.nextInt(5); because it starts at 2 and increases by 3 each step for 5 steps, covering the sequence 2, 5, 8, 11, and 14.

Question 12

In a class containing methods with the same name, the methods are distinguished by ________.
A) Number of arguments
B) Types of arguments
C) Return type
D) (a) and (b)
E) (b) and (c)

Accepted Answer

The methods are distinguished by both the number and types of arguments they take, so options (a) and (b) are both correct. The return type alone is not enough to distinguish between methods with the same name. Therefore (c) is not the best choice. Option (e) is incorrect because it combines the correct answer with an incorrect one.

Question 13

Math static method random generates a random double value in the range from 0.0
A) up to but not including 1.0
B) up to and including 1.0
C) up to and including 100.0
D) up to but not including 100.0

Accepted Answer

The documentation for the static method random states that it generates a random double value between 0.0 (inclusive) and 1.0 (exclusive), meaning it will generate values up to but not including 1.0.

Question 14

Which of the following statements describes block scope?
A) It begins at the opening { of the class declaration and terminates at the closing }.
B) It limits label scope to only the method in which it is declared.
C) It begins at the identifier's declaration and ends at the terminating right brace (}).
D) It is valid for one statement only.

Accepted Answer

Block scope refers to the area within a code block enclosed by a pair of braces ({ }). It begins at the identifier's declaration and ends at the terminating right brace (}). Variables declared within this block are only accessible within the block and are destroyed once the block is exited.

Question 15

Method calls cannot be distinguished by ________.
A) method name
B) return type
C) parameter lists
D) method signature

Accepted Answer

Method calls are distinguished by their method signatures, which include the method name and the parameter list. The return type is not part of the method signature, so methods cannot be distinguished by their return types alone.

Question 16

Which of the following is not a package in the Java API?
A) java.component
B) java.awt.event
C) javax.swing.event
D) java.lang

Accepted Answer

There is no package named java.component in the Java API, while the other options are all valid packages in the API.

Question 17

Which of the following methods are overloaded with respect to one another? public int max (int a, int b) { … }
Public double max (double a, double b) { … }
Public int max (int a, int b, int c) { … }
Public double max (double a, double b, double c) { … }
A) A and B are overloaded; C and D are overloaded.
B) A and C are overloaded; B and D are overloaded.
C) A, B and C are overloaded.
D) All four methods are overloaded.

Accepted Answer

Overloading occurs when two or more methods in the same class have the same name but different parameters. All four methods here have the same name "max" but differ in their parameter lists either by type or number of parameters, thus they are all overloaded with respect to one another.

Question 18

The identifiers in an enumeration ________.
A) must be unique.
B) may be duplicated.
C) must be lowercase letters and cannot contain numbers.
D) must be uppercase letters and cannot contain numbers.

Accepted Answer

Identifiers in an enumeration must be unique. This means that each identifier must be different from every other identifier in the same enumeration. Duplicated identifiers would lead to confusion and errors in the code. The other options (C and D) are not accurate as there are no restrictions on the format or case of identifiers in an enumeration, as long as they are unique.

Quiz 6: Methods: a Deeper Look

An overloaded method is one that ________.

A Java class can have which of the following methods? A. void foo(int a) B. void foo(int a, int b) C. void foo(double a) D. void foo(double a, double b) E. void foo(int b)

Which statement below could be used to simulate the outputs of tossing a quarter to get heads or tails? Suppose randomNumbers is a SecureRandom object.

Overloaded methods always have the same _________.

Which of these statements best defines scope?

The jjava.text package contains classes for manipulating all of the following items except ________.

Identifiers in Java have and scopes?

Which of the following statements is false?

Which statement below could be used to simulate the outputs of rolling a six-sided die? Suppose randomNumbers is a SecureRandom object.

A set of named constants that start with the value 0 for the first constant and increment by 1 for each subsequent constant can be declared as a(n) ________.

Which statement creates a random value from the sequence 2, 5, 8, 11 and 14. Suppose randomNumbers is a SecureRandom object.

In a class containing methods with the same name, the methods are distinguished by ________.

Math static method random generates a random double value in the range from 0.0

Which of the following statements describes block scope?

Method calls cannot be distinguished by ________.

Which of the following is not a package in the Java API?

Which of the following methods are overloaded with respect to one another? public int max (int a, int b) { … } Public double max (double a, double b) { … } Public int max (int a, int b, int c) { … } Public double max (double a, double b, double c) { … }

The identifiers in an enumeration ________.