Ch 1
Analyze the following code. I: public class Test{ public static void main(String[] args) { System.out.println("Welcome to Java!"); } } II: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } }
Both I and II can compile and run and display Welcome to Java, but the code in I has a better style than II.
Which of the following lines is not a Java comment? (choose all that apply)
** comments ** -- comments
Which of the following lines is not a Java comment?
-- comments *** comments ***
The extension name of a Java bytecode file is
.class
The extension name of a Java bytecode file is ________.
.class
The extension name of a Java source code file is
.java
________ translates high-level language program into machine language
A compiler
________ is a software that interprets Java bytecode.
Java virtual machine
The speed of the CPU is measured in ________. (choose all that apply)
Megahertz Gigahertz
________ is a device to connect a computer to a local area network
NIC
________ is a device to connect a computer to a local area network (LAN).
NIC
Java ________ can run from a Web browser.
applets
The main method header is written as:
public static void main(String[] args)
Which of the following statements is correct to display Welcome to Java on the console? (choose all that apply)
System.out.println("Welcome to Java"); System.out.print("Welcome to Java");
Suppose you define a Java class as follows: public class Test { } In order to compile this program, the source code should be stored in a file named ________.
Test.java
A Java application must have a main method.
True
A Java program block starts with an open brace ({) and ends with a closing brace (}).
True
Java is an object-oriented programming language.
True
Java was originally developed by a team led by James Gosling at Sun Microsystems.
True
The keywords in Java are all in lowercase.
True
The public classname must be the same as the filename that contains the class.
True
________ is an operating system.
Windows XP
Every statement in Java ends with ________.
a semicolon (;)
Why do computers use zeros and ones?
because digital devices have two stable states and it is natural to use one state for 0 and the other for 1
The ________ loads Java bytecode to the memory.
class loader
Which of the following are storage devices?
floppy disk hard disk flash stick CD-ROM
You use ________ to run a Java program
java
Which JDK command is correct to run a Java application in ByteCode.class?
java ByteCode
The JDK command to compile a class in the file Test.java is
javac Test.java
The command to compile a class in the file Test.java is
javac Test.java
Computer can execute the code in ________.
machine language
Which of the following are the reserved words? (choose all that apply)
void public static class
The extension name of a Java source code file is ________.
.java
The decimal value 16 is ________ in hex.
10
The decimal value 5 is ________ in binary.
101
Decimal number 10 is binary number ________.
1010
Hexadecimal number A1 is binary number ________.
10100001
The binary representation of decimal 49 is ________.
110001
The hex value 7A is ________ in binary.
1111010
The binary value 10011 is ________ in hex.
13
Decimal number 20 is hexadecimal number ________.
14
Hexadecimal number A1 is decimal number ________.
161
The hex value 1A is ________ in decimal.
26
Four bytes have ________ bits.
32
One byte has ________ bits.
8
Binary number 1001 is decimal number ________.
9
Binary number 1001 is hexadecimal number ________.
9
The binary value 1001 is ________ in decimal.
9
Which of the following statements is true?
A Java applet can be executed from a Web browser
A block is enclosed inside ________.
Braces
________ is the brain of a computer.
CPU
Which of the following statements is correct?
Every statement in a program must end with a semicolon.
A Java interpreter is a program that translates Java source code into Java bytecode.
False
Java source code can be executed on a Java Virtual Machine.
False
The compiler generates bytecode even if the program has syntax errors.
False
________ is the physical aspect of the computer that can be seen.
Hardware
The ________ method displays a message dialog box. (choose all that apply)
JOptionPane.showMessageDialog(null, "Welcome to Java!"); JOptionPane.showMessageDialog(null, "Welcome to Java!", "Example 1.2 Output", JOptionPane.INFORMATION_MESSAGE);
________ is Architecture-Neutral.
Java
________ is interpreted.
Java
________ is an object-oriented programming language. (choose all that apply)
Java C++
________ contains predefined classes and interfaces for developing Java
Java API
________ contains predefined classes and interfaces for developing Java programs.
Java API
________ provides an integrated development environment (IDE) for rapidly developing Java programs. Editing, compiling, building, debugging, and online help are integrated in one graphical user interface.
Java IDE
________ consists of a set of separate programs for developing and testing Java programs, each of which is invoked from a command line.
Java JDK
Java compiler translates Java source code into ________.
Java bytecode
________ is a technical definition of the language that includes the syntax and semantics of the Java programming language.
Java language specification
________ is a program that runs on a computer to manage and control a computer's activities.
Operating system
________ are instructions to the computer. (choose all that apply)
Programs Software
________ are secondary storage. (choose all that apply)
RAM CD floppy disk
Java was developed by ________.
Sun Microsystems