Decision Sciences Analyst Interview Questions and Answers

The 4 pillars of OOPs concepts in Java are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hiding implementation details and showing only necessary information. Example: Abstract class

• Encapsulation: Wrapping data and code into a single unit. Example: Private variables and methods

• Inheritance: Acquiring properties and behavior of a parent class. Example: Child class inheriting from a parent class

• Polymorphism: Ability of an object to take many forms. Examp...read more

Equals method compares the content of objects while == compares the reference of objects in Java.

• Equals method is used to compare the content of two objects in Java.

• == operator is used to compare the reference of two objects in Java.

• Equals method is overridden in most of the classes to provide meaningful comparison.

• Example: String s1 = new String("Hello"); String s2 = new String("Hello"); s1.equals(s2) will return true while s1 == s2 will return false.