Java Mock Quiz Excellence
Java skills test
Questions and Answers
- 1.
Which of the following process converts Java programming language code to a set of bytecodes?
- A.
Bytecode verification
- B.
Compilation
- C.
Class loading
- D.
Execution
Correct Answer
B. CompilationExplanation
Compilation is the process that converts Java programming language code into a set of bytecodes. During compilation, the Java code is translated into a lower-level representation called bytecode, which is a platform-independent format. This bytecode can then be executed on any system that has a Java Virtual Machine (JVM) installed. The bytecode verification, class loading, and execution are subsequent steps in the process of running a Java program, but the initial step of converting the code into bytecode is achieved through compilation.Rate this question:
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- 2.
Which of the following values is a type of the boolean data type?
- A.
'true'
- B.
"true"
- C.
True
- D.
Boolean
Correct Answer
C. TrueExplanation
The value "true" is a type of the boolean data type. In programming, boolean is a data type that represents two possible values: true or false. It is commonly used for logical operations and conditional statements. In this case, "true" is enclosed in quotation marks, which suggests that it is a string rather than a boolean value. However, the question is asking for a value that is a type of the boolean data type, and the correct answer is "true" without the quotation marks.Rate this question:
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- 3.
Your program needs to use the App class present in the foo.bar package. Which of the following statements imports the class to your program?
- A.
Import App;
- B.
Imports foo.bar.App;
- C.
Import foo.bar.*;
- D.
Import foo.*;
Correct Answer
C. Import foo.bar.*;Explanation
The statement "import foo.bar.*;" imports all the classes present in the foo.bar package to the program. This allows the program to access and use the App class from the foo.bar package.Rate this question:
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- 4.
Consider the following statements: Statement A: String is a primitive data type to represent a sequence of characters. Statement B: You can declare a String variable as: String str="I am a String"; Select the correct option for the preceding statements:
- A.
Stetement A is true while Statement B is false.
- B.
Both Statement A and Statement B are true.
- C.
Statement A is false while Statement B is true.
- D.
Both Statement A and Statement B are false.
Correct Answer
C. Statement A is false while Statement B is true.Explanation
Statement A is false because String is not a primitive data type, it is a class in Java. It is used to represent a sequence of characters. Statement B is true because you can declare a String variable by assigning a sequence of characters to it using double quotes.Rate this question:
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- 5.
Consider the following statements: Statement A: A constructor must have the same name as that of the class. Statement B: The return type of a constructor must be void. Select the correct option for the preceding statements:
- A.
Both Statement A and Statement B are true.
- B.
Both Statement A and Statement B are false.
- C.
Statement A is true while Statement B is false.
- D.
Statement A is false while Statement B is true.
Correct Answer
C. Statement A is true while Statement B is false.Explanation
A constructor must have the same name as that of the class, which means that the name of the constructor should be exactly the same as the name of the class it belongs to. This is true in Java and many other programming languages. However, the return type of a constructor is not specified and it is not void. In fact, a constructor does not have a return type at all. It is used to initialize objects of a class and is automatically called when an object is created.Rate this question:
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- 6.
Select the correct integer length for the int data type.
- A.
8 bits
- B.
16 bits
- C.
32 bits
- D.
64 bits
Correct Answer
C. 32 bitsExplanation
The correct integer length for the int data type is 32 bits. This means that an int variable can store whole numbers ranging from -2,147,483,648 to 2,147,483,647. This is the standard size for the int data type in many programming languages, including C and Java.Rate this question:
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- 7.
Which of the following is a valid Java identifier?
- A.
$const
- B.
Const
- C.
Long
- D.
new
Correct Answer
A. $constExplanation
The valid Java identifier is "$const". In Java, an identifier is a name used to identify a variable, method, class, or other program elements. It must start with a letter, underscore, or dollar sign, and can be followed by any combination of letters, digits, underscores, or dollar signs. Therefore, "$const" is a valid identifier as it starts with a dollar sign and is followed by alphabets.Rate this question:
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- 8.
The _____________ option of the compiler enables you to compile class files to a different directory than that of the source files.
- A.
-cp
- B.
-source
- C.
-g
- D.
-d
Correct Answer
D. -dExplanation
The "-d" option of the compiler enables you to compile class files to a different directory than that of the source files. This option is useful when you want to separate the compiled files from the source files, allowing for better organization and management of the project. By specifying a different directory using the "-d" option, you can easily locate and access the compiled class files without cluttering the source code directory.Rate this question:
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- 9.
Select the correct option that shows the command to execute the MyApp Java class.
- A.
Java class=MyApp
- B.
Javac MyApp.java
- C.
Java MyApp.java
- D.
Java MyApp
Correct Answer
D. Java MyAppExplanation
The correct option is "java MyApp". This is because the "java" command is used to execute a Java program, and "MyApp" is the name of the Java class that needs to be executed.Rate this question:
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- 10.
To compile and execute Java programs, you need to set the PATH environment variable to ___________________.
- A.
The working directory that contains the source files of the program.
- B.
The java_root/lib directory, where java_root is the installation directory of the Java technology software.
- C.
The java_root/bin directory, where java_root is the installation directory of the Java technology software.
- D.
The installation directory of the Java technology software.
Correct Answer
C. The java_root/bin directory, where java_root is the installation directory of the Java technology software.Explanation
To compile and execute Java programs, you need to set the PATH environment variable to the java_root/bin directory, where java_root is the installation directory of the Java technology software. This is because the java_root/bin directory contains the necessary executable files, such as javac (the Java compiler) and java (the Java virtual machine), that are required to compile and run Java programs. By setting the PATH environment variable to this directory, the system knows where to find these executable files when you try to compile and execute Java programs from the command line.Rate this question:
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Current Version
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Mar 19, 2023Quiz Edited by
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Dec 25, 2009Quiz Created by
Mastermind420420
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