BPSC TRE – Java Programming & OOP Concepts

Question 46

MCQ · Single Correct 1 mark

Which statement about Java constructors is accurate?

A Constructors can be overloaded, but they cannot be overridden or declared static B Constructors are inherited by subclasses during class extension C Constructors must specify a return type of void D More than one of the above E None of the above

Question 47

MCQ · Single Correct 1 mark

What is the function of the System.gc() method in Java?

A It suggests to the JVM that Garbage Collection be run, though execution is not guaranteed immediately B It instantly forces immediate synchronous deletion of all heap objects C It clears all static memory variables from class loader D More than one of the above E None of the above

Question 48

MCQ · Single Correct 1 mark

What is the key difference between String, StringBuilder, and StringBuffer in terms of performance and thread safety?

A String is mutable; StringBuilder and StringBuffer are both immutable B StringBuffer is faster than StringBuilder because it avoids synchronization C A valid alternative answer not listed D More than one of the above E None of the above

Question 49

MCQ · Single Correct 1 mark

Which wrapper class method in Java converts a String representation of a number into a primitive int value?

A Integer.parseInt(String s) B Integer.valueOf(String s) C String.toInt(String s) D More than one of the above E None of the above

Question 50

MCQ · Single Correct 1 mark

In Java 8, what syntax operator is used to write concise $\Lambda Expressions$?

A Scope resolution operator (::) B Dot operator (.) C A valid alternative answer not listed D More than one of the above E None of the above