Practice · Computers, Programs, and the Java Language

Q1

Which of the following is not a hardware component?

A CPU B RAM C Compiler D Hard disk

Q2

Which statement about main memory (RAM) is correct?

A It keeps its contents when the power is switched off. B It is volatile and holds the program and data during execution. C It is slower than a hard disk. D It is used to store files permanently.

Q3

Which component of the CPU performs arithmetic and logical operations?

A ALU B Control unit C Cache D Bus

Q4

One byte consists of how many bits?

A 4 B 8 C 16 D 1024

Q5

Which of the following is system software?

A A web browser B A spreadsheet C An operating system D A payroll program

Q6

Which device is both an input and an output device?

A Keyboard B Monitor C Touchscreen D Mouse

Q7

What is the correct name for a program that translates an entire high-level program into object code before execution?

A Interpreter B Compiler C Assembler D Loader

Q8

A ________ is a program that executes compiled Java code on a specific platform.

A Java Virtual Machine B Java compiler C Java programming manual D Text editor

Q9

The keyword ________ is required in order to declare a class.

A public B private C class D All of the above

Q10

What file does the Java compiler produce from Payroll.java?

A Payroll.exe B Payroll.class C Payroll.obj D Payroll.jar

Q11

Bytecode is best described as:

A machine language for a particular processor; B an intermediate, platform-independent code understood by the JVM; C the source code after comments have been removed; D a compressed archive of Java classes.

Q12

Which command correctly runs a compiled class named Demo?

A javac Demo B java Demo.class C java Demo D run Demo.java

Q13

Java is often described as both compiled and interpreted because:

A the compiler runs twice; B source is compiled to bytecode, which the JVM then executes; C it can be written in two different syntaxes; D the JDK contains two compilers.

Q14

Which of the following best explains Java's portability?

A Java source files are small. B The same bytecode runs on any platform that has a JVM. C Java programs are recompiled automatically on every machine. D Java uses only ASCII characters.

Q15

What is the relationship between the JDK and the JRE?

A They are the same thing. B The JRE contains the JDK. C The JDK contains the JRE plus development tools such as the compiler. D The JDK is required to run any Java program.

Q16

A public class named StudentRecord must be saved in a file named:

A studentrecord.java B StudentRecord.java C StudentRecord.txt D any name

Q17

Which of the following method signatures is a valid declaration of an entry point in a Java application?

A public static void main() B private static void main(String[] args) C public void main(String[] args) D public static void main(String... data)

Q18

What is the output of the following application?

public class Greeting {
    public static void main(String[] args) {
        System.out.print("Good ");
        System.out.print("morning");
        System.out.println("!");
        System.out.println("Class");
    }
}

A Good morning! then Class on the next line B Good morning ! Class on four lines C Goodmorning!Class on one line D The code does not compile.

Q19

Which of the following is a legal Java identifier?

A 2ndPlace B total-sum C _count D class

Q20

Why can new not be used as a variable name?

A It is too short. B It is a reserved word. C It starts with a lower-case letter. D It is already used by System.out.

Q21

Which pair of identifiers refers to two different things in Java?

A count and count B Count and count C a_b and a_b D None of them

Q22

Which symbol terminates a Java statement?

A : B ; C . D }

Q23

What is the purpose of a pair of braces { } in a Java program?

A To group statements into a block. B To mark a comment. C To declare an array. D To separate parameters.

Q24

Which comment form is used to generate API documentation?

A // text B /* text */ C /** text */ D 

Q25

What happens to comments when a program is compiled?

A They are translated into bytecode. B They are ignored by the compiler. C They are printed at run time. D They cause a warning.

Q26

The difference between System.out.print and System.out.println is that:

A println adds a line break after the output; B print is faster; C println can only print strings; D there is no difference.

Q27

Missing a semicolon at the end of a statement produces:

A a logic error B a run-time error C a compile-time error D no error

Q28

Dividing an integer by zero at run time produces:

A a compile-time error B a run-time error C a logic error D a warning only

Q29

A program that computes the average of three numbers as (a + b + c) / 2 contains:

A a syntax error B a logic error C a run-time error D no error

Q30

Which type of error can the compiler not detect?

A Misspelled keyword B Missing brace C Wrong formula D Undeclared variable

Q31

Put the following steps of program development in the correct order: (i) run, (ii) edit source code, (iii) compile, (iv) test and debug.

A ii, iii, i, iv B iii, ii, i, iv C ii, i, iii, iv D i, ii, iii, iv

Q32

An IDE (Integrated Development Environment) typically combines:

A an editor, a compiler and a debugger; B an operating system and a browser; C a CPU and main memory; D a compiler and a spreadsheet.

Q33

Which statement about the main method's parameter is true?

A It must be called args. B It must be of type String[] (or varargs String...); its name is your choice. C It must be of type int[]. D It may be omitted entirely.

Q34

What is the result of compiling and executing the following class?

public class Test {
    public static void Main(String[] args) {
        System.out.println("Running");
    }
}

A It prints Running. B It compiles but fails at run time because no main method is found. C It does not compile. D It prints nothing and exits normally.

Q35

Which of the following is stored in secondary storage rather than in RAM?

A The variables of a running program B A saved .java file C The current instruction being executed D Intermediate results of a calculation

Q36

Which statement is false?

A A compiler reports syntax errors before the program runs. B An interpreter translates and executes one statement at a time. C Machine language depends on the processor. D A high-level language program runs directly on the CPU without translation.

Q37 Short answer

In two or three sentences, explain the difference between source code and object code, and name the tool that converts one into the other in Java.

Q38 Short answer

Explain, in your own words, why a .class file produced on a Windows machine can be executed on a Mac without being recompiled.

Q39 Short answer

Give one example each of a compile-time error, a run-time error and a logic error in a program that computes a student's average mark.

Q40 Programming

Write a complete Java program in a file Introduction.java that prints your name on the first line, your student ID on the second, and the sentence I am learning Java. on the third, using exactly one println per line. Add a javadoc comment above the class stating what the program does.