JAVA CONCEPTS

Important Java Mcq 1

The expression “java” + 1 + 2 + 3 evaluates to ________.

a. java5

b. java123

c. java12

d. Error

Answer:

b. java123

Explanation:

In java, whenever we concatenate string followed by integers, all the integers get concatenated.

Which keyword is used to import a package from the Java API library?

a) lib b) package c) getlib d) import Answer d) import

Which of the following is not a valid interface?

a. ResultSet b. DriverManager c. Statement d. Connection Answer: b. DriverManager Explanation: DriverManager is a class that acts as an interface between users and Drivers. It

All subclasses are a subtype in object-oriented programming.

a) True b) False Answer b) False Explanation: A subtype is something that is substituted for and behaves as its parent type. All subclass may

Which statement is true for object code?

i) It is used as its fundamental building block ii) Similar objects are classified using a concept of class iii) Polymorphism and abstraction are not