Programming In Java Week 4 NPTEL Assignment Answers 2025

NPTEL Programming In Java Week 4 Assignment Answers 2024

1. Which is the keyword used to specify the default access modifier in java?

a. default
b. DEFAULT
c. package
d. “There is no keyword”

Answer: d
Explanation: In Java, the default access modifier does not have a specific keyword. If no access modifier is mentioned, it is considered “default” (package-private). Hence, there’s no keyword to explicitly declare it.

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2. What is the output of the Java program with access modifiers?

a. FOUR
b. Runtime Error
c. null
d. Compiler Error

Answer: d
Explanation: If access modifiers are used improperly or violate encapsulation, the compiler throws an error, preventing the code from executing.

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3. What is the output of the below Java Code Snippet with access modifiers?

a. Weeks = 0
b. Weeks = 12
c. No Error, blank output
d. Compiler error

Answer: b
Explanation: Assuming the code correctly sets the value of Weeks to 12 and has appropriate access, it will print Weeks = 12.

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4. Which of the following is the correct representation of access modifiers in order of increasing visibility?

a. private < default < protected < public
b. private < protected < default < public
c. public < protected < default < private
d. protected < default < private < public

Answer: a
Explanation: The correct visibility order is:
private < default (package-private) < protected < public

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5. Which of the following package stores all the standard java classes?

a. java.util
b. java.lang
c. java.java
d. java.packages

Answer: b
Explanation: java.lang contains core classes like Object, String, System, etc., and is automatically imported.

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6. Which of the following is/are true about packages in Java?

1. Every class is part of some package.
2. All classes in a file are part of the same package.
3. If no package is specified, the classes in the file go into a special unnamed package.
4. If no package is specified, a new package is created with folder name of class and the class is put in this package.

a. Only 1, 2 and 3
b. Only 1, 2 and 4
c. Only 4
d. Only 1 and 3

Answer: a
Explanation: Statements 1, 2, and 3 are correct. There is no automatic creation of a named package based on folder name.

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7. What is the output of following Java program?

a. Compiler Error
b. Runtime Error
c. Welcome!
d. None of the above

Answer: c
Explanation: The program runs without error and prints “Welcome!”, meaning all access rules are properly followed.

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8. Which of these access specifiers can be used for an interface?

a. Public
b. Protected
c. private
d. All of the mentioned

Answer: a
Explanation: Interfaces in Java can only be public or package-private (default). They cannot be private or protected.

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9. Which of the following is the correct way of implementing an interface salary by class manager?

a. class Java extends NPTEL {}
b. class Java implements NPTEL {}
c. class Java imports NPTEL {}
d. none of the mentioned

Answer: b
Explanation: A class implements an interface using the implements keyword. extends is for classes or abstract classes.

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10. What will be the output of the following Java program?

a. 0
b. 2
c. 4
d. Compiler Error

Answer: c
Explanation: If the code performs a loop or calculation leading to 4, and there’s no syntax error, it will output 4.