Learning Outcomes

• Core Java Interview Questions and Answers

Contents

Core Java Interview Questions and Answers part of full stack java developer course.

Q & As

What is difference between for loop and iterator? What is difference between ArrayList and LinkedList? Diff. Hashset vs Hashmap, StringBuffer vs StringBuilder How we avoid duplicate entries equals() method from which class How and when to use equals method Can we override constructor What is mutable and immutable Can we override static method? explain in details can we override instance method? What is checked and unchecked exception? What is marker interface? give example What is functional interface? give example? What is serialization? What is deserialization? What is transient keyword? What is difference between comparator and comparable? What is difference between prepareStatement and Statement? What is difference between Enumeration and Iterator? Internal working of hashmap? write a program to iterate the elements of ArrayList write a program to iterate the elemeents of HashMap Demonstrate the example of comparable interface? demonstrate the exmaple of Comparator interface? can we call start() method twice in a Thread? can call run method of thread explicitly? what happen if called? what is deadlock? how to avoid it? what is difference synchronized method and synchronized block? What is daemon thread? What is difference between sleep and wait? What are the methods of object class? what is use of final keyword? what is use of finally?