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 8 Functional Programming Interview questions focusing on FP. Getting a good handle on Java OOP concepts and FP concepts are very important NOT only from writing quality code perspective, but also from job interviews perspective to be able to do well in written tests & technical interviews. … Read...
Here are 7 rules to remember regarding Java Generics to understand Generics and handle interview and coding questions on Core Java. Object <– Fruit <– (Orange, Mango, etc siblings) Rule 1: Java generics differ from C++ templates. Java generics (at least until JDK 8), … Read more ›...
The java.util.function package provides the below functional interfaces. These are used in lambda functions & saves you time by you not having to create your own. You will often find one of these below serve your requirement. Why Function, Supplier, Consumer & Predicate? We know that Java 8 introduced an...
Q1. How would you go about choosing the right data types for your application?
A1. Java is what is known as a strongly typed language. This means Java only accepts specific values within specific variables or parameters. Some languages, such as JavaScript, PHP,
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Java does not have a sizeof operator like C++ does. Java uses automatic memory management known as the Garbage Collection, hence it is not that important to evaluate size of various objects. But, for the purpose of learning & fixing any potential memory issues, I have used “jvisualvm”, … Read...
A Trade goes through 3 state changes – placed, filled, and settled. Let’s solve this simple problem using both OOP & FP approaches.
Place –> Fill –> Settle
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package com.shared; public class Trade { private final String name; private final int qty; public Trade(String name, int qty) { this.name = name; this.qty = qty; } public String getName() { return name; } public int getQty() { return qty; } @Override public String toString() { return "Trade [name=" + name + ", qty=" + qty + "]"; } } |
OOP approach by mutating the state
State changes are maintained via a variable named “
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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 ›...
Choosing the right data structure is vital to get the job done with proper space vs performance trade-offs. Q1. What are the common data structures, and where would you use them? A1. Deterministic Data Structures like Arrays, … Read more ›...
A stream is an infinite sequence of consumable elements (i.e a data structure) for the consumption of an operation or iteration. Any Collection<T> can be exposed as a stream. It looks complex, but once you get it, it is very simple. The operations you perform on a stream can either...
This is a companion post to 8 Java Memory Management Interview Q&A demonstrating a memory leak scenario step by step with jvisualvm, which is a free profiling tool that gets shipped with JDK. Step 1: Code that causes memory leak Here is a sample code that causes memory leak. …...
Java code to convert given input values from KM to Meter, Meter to Centimetres, etc. OOP approach using the strategy design pattern Step 1: Define an interface.
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package com.oop.eg2; public interface Converter<T> { T convert(T input); |
Step 2: Define a generic “MyMetricConverter” that implements the “Converter”.
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package com.oop.eg2; import java.math.BigDecimal; public abstract class MyMetricConverter implements Converter<Double> { @Override public Double convert(Double input) { BigDecimal result = BigDecimal.valueOf(input).multiply(BigDecimal.valueOf(getConversionRate())); return result.doubleValue(); } abstract double getConversionRate(); } |
Step 3: Define different strategy classes that return different conversion rates....
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