Top 5 Skills and Topics to Crack Tech Coding Interviews in 2022 [UPDATED]

Hello folks, are you thinking of a new job in 2022 and looking for which topics and skills to prepare for your coding interview? There is no doubt cracking the Coding interviews of tech companies like Google, Microsoft, and Amazon is very hard. However, you can still break it by carefully planning and preparing the essential skills which matter most, like Data structures and Algorithms, System Design, Multithreading and Concurrency, SQL and Database design, and of course, problem-solving skills. Being an author of Java and a programming blog, I often receive queries about preparing for coding interviews? How to pass Google or Microsoft Software Developer interviews? Or how can I get a software development job on Amazon or Facebook? After answering many of my readers one by one on Facebook and LinkedIn, I thought to put together a list of essential topics for coding interviews.

Top 50 Java Programs from Coding Interviews

Coding is an integral part of any programming job interviews, and Java development interviews are no exception. I would even suggest you should never hire anyone without testing their coding skill, coding is also an art, and more often than a good code is an excellent developer as well. If you look at tech giants like Amazon, Facebook, and Google they thoroughly test the coding skill of any developer they hire, notably Amazon who first send online coding exercises to filter Java programmers who can code. This online test usually gives you requirements and ask you to write a program in a limited time, usually 2 to 3 hours. The application should meet the output provided by the exercise itself. These type of tasks are very tough to crack if you don't have excellent coding skill.

How to Implement Stack Data Structure in Java? Example Tutorial

The stack is one of the popular data structures which supports LIFO (Last In First OUT) operation. Due to the LIFO advantage, you can use a stack data structure to convert a recursive algorithm to an iterative one. The stack data structure is very easy to implement using an array or linked list, but you don't have to implement it on your own because Java already provides a Stack implementation in java.util.Stack class. This class is a subclass of the Vector class and you should use it whenever you need Stack for your production code, there is no point in inventing the wheel again when the focus is on developing your application.

2 Ways to check If String is Palindrome in Java? Recursion and Loop Example Tutorial

A String is said to be Palindrome if it is equal to itself in reverse order. You can use this logic to check if String is Palindrome or not. There are two common ways to find if a given String is Palindrome or not in Java, first by using for loop, also known as an iterative algorithm, and second by using recursion, also known as a recursive algorithm. The crux of this problem lies in how do you reverse String in Java? because once you have the String in reverse order, the problem is reduced to just comparing itself with the reversed String. If both are equal then the given String is Palindrome otherwise it's not. Also whether your solution is iterative or recursive will also determine by implementing this logic.

How to Convert Fahrenheit to Celsius in Java with Example

In this Java tutorial, you will learn how to write a program to convert Fahrenheit to Celsius in Java. Fahrenheit is a thermodynamic temperature scale, where the freezing point of water is 32 degrees Fahrenheit (°F) and the boiling point of water is 212°F (at standard atmospheric pressure). This puts the boiling and freezing points of water exactly 180 degrees apart. Therefore, a degree on the Fahrenheit scale is 1/180 of the interval between the freezing point and the boiling point of water. Absolute zero is defined as -459.67°F. If you know, in the Celsius scale, the freezing point of water is at 0ºC and the boiling point of water is at 100ºC. By using these facts, you can easily deduce a formula to convert Fahrenheit temperature into Celsius.

How to Count number of Set bits or 1's of Integer in Java? Example

There are multiple ways to count the number of 1's or set bits in an integer number in Java. You can use a bitwise and bit shift operator on your own, or, you can use Java API to count the number of set bits. Java 1.5 added two utility methods called bitCount(int i) which returns a number of 1's in your integer number, java.lang.Long class has a similar bitCount(long number) for long primitives. As I have said earlier, Coding questions are an important part of any Java interview, and from that recursion and bitwise operations are most popular. 

How to Add Two Integer Numbers without using Plus + or ++ Arithmetic Operator in Java - Recursion example

In this article, we will take a look at another interview question about adding two numbers, but without using the + or ++ operator. The interview starts with a simple statement, Can you write a function to add two numbers (integers) without using + or plus arithmetic operator in Java? If you are good at maths, it wouldn’t take more than a second to say that, we can use subtraction or - operator to add two numbers because a-(-b)== a+b. Well, that’s correct, but the real question starts when the interviewer quickly points out that, you can not use any arithmetic operator including +,-,*,/++, or --.