How to Implement a Power Function in Java - Coding Problems

Even though the Java library has a power function, Math.pow() to calculate the power of a number in Java, it's a common coding exercise for Java programmer to implement a power function. The java.lang.Math.pow(double a, double b) returns the value of the first number raised to the power of the second number and you need to do the same. In other words, write a function to calculate the power of integer numbers for simplicity.

Top 20 System Design Interview Questions for Java Programmers

System design questions are an important part of programming job interviews and if you want to do well, you must prepare this topic. In the past, when I shared my list of programming interview questions, I have shared a couple of System design questions but my readers kept asking me for more questions, as it is a hard topic to master and more and more practice is needed. I had my own list of questions which I have collected from various interviews with friends and colleagues but I needed more questions for this article and my own preparation then I stumbled upon Grokking System Design Interview course. It's an excellent resource because it not only gives you a lot of System design question but also provide all the knowledge and tools you need to solve those questions.

Java - String charAt Example - How to get first and last characters

The charAt(int index) method of java.lang.String class can be used to retrieve a character from given index. The method returns a character, you can see its return type is char. The index starts from zero and ranges to length() - 1 where length() return the length of String. It's similar to an array where the first element is stored at zeroth index and the last element is stored at length -1 index because String is nothing but backed by a character array. If the value of the index is invalid i.e. it's lower than zero or negative or higher than length - 1 then this method throws an IndexOutOfBoundsException. In this article, I'll show you a couple of example of how to use the charAt() method to retrieve a character from String in Java.