Top 50 core Java interview questions covering core Java concepts with diagrams, code, examples, and scenarios. If you don’t get these Java interview questions right, you will not be getting an offer.
== Vs equals(…)
Q1. What is the difference between “==” and “equals(…)” in comparing Java String objects?
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The focus is on Java OOP interview questions and answers. Q11. What is the difference between constructors and other regular methods? A11. Constructors must have the same name as the class name and cannot return a value. The constructors are called only once per creation of an object while regular...
Focus is on Java classes, interfaces and generics the interview questions and answers style. Java classes and interfaces are the building blocks. Q24. What happens when a parent and a child class have the same variable name? A24. … Read more ›...
As a Java developer, you may not need to know how the JVM works, but the most important topic that you must know is Java Garbage Collection. How the Garbage Collection and object referencing work in Java. Q37. What do you know about the Java garbage collector? … Read more...
Q43. What can you tell about the performance of a HashMap compared to a TreeMap? Which one would you prefer? A43. A balanced tree does have O (log n) performance. The TreeMap class in Java maintains key/value objects in a sorted order by using a red-black tree. … Read more...
Multithreading is one of the important features of Java, and multithreading interview Q&As can reveal a lot about your depth of core Java knowledge. Most importantly, it is not easy to grasp multithreading concepts without lots of hands-on experience. Let’s start with the beginner basics & then get into Java concurrency management interview Q&As for the experienced.
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Java Collection interview questions and answers and Java String class interview questions and answers are must know for any Java developer as these two APIs are the most frequently used in your Java application code. You can’t write any decent Java application without these 2 APIs.
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Java interview questions & answers on multithreading scenarios to judge your experience in building applications with concurrency in mind. Q1. Can you give some scenarios where you built concurrent systems? A1. In a concurrent system different threads run concurrently, … Read more ›...
7 Things you must know about Java locks and synchronized key word summarizes the key basics. #1. Each Java class and object (i.e. instance of a class) has an intrinsic lock or monitor. Don’t confuse this with explicit lock utility class that were added in Java 1.5, … Read more...
Q1. Have you seen job advertisements requiring Java candidates to work in real-time or high volume transaction processing systems? A1. If you are applying for such jobs, you can be quizzed on Big O notation. Here are some basics to brush up on. … Read more ›...
Java Collections interview questions and answers and Java String class interview Q&As are must know as you can’t write any decent Java application without these 2 APIs. This post focuses on Java Collection interview Q&As on differences between X and Y based on the Java Collection Framework (i.e. … Read...
Java modifiers like final, finally, const, volatile, and transient are very popular with the job interviewers. You will see why because of the possible drill down questions. Q1. What is the difference between ‘final‘ and ‘const‘ modifiers on a variable? … Read more ›...
Java Garbage Collection interview questions & answers to ascertain your depth of Java knowledge in building industry strength Java applications. Determining optimal Garbage Collection (GC) settings is critical to achieve high throughput & low latency.
Q1. In which part of memory does Java Garbage Collection (i.e.
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