Preparing for Java Interview?

My books Grokking the Java Interview and Grokking the Spring Boot Interview can help

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How to count a number of words in given String in Java? [Solved]

Can you write a method in Java that accepts a String argument and returns a number of words in it? A word is a sequence of one or more non-space characters i.e. any character other than '' (empty String). This should be your method signature:

public int count(String word);

This method should return 1 if the input is "Java" and return 3 if the input is "Java, C++, Python". Similarly a call to wordCount("    ") should return 0. 

How to use String.matches() with Regular Expression in Java? Example Tutorial

String Matching Example in Java
The string matches method in Java can be used to test String against regular expressions in Java. The string matches() method is one of the most convenient ways of checking if a String matches a regular expression in Java or not. Quite often we need to write code that needs to check if String is numeric, Does String contains alphabets e.g. A to Z or a to Z, How to check if String contains a particular digit 6 times, etc. There are so many cases in Java programming where we need a regular expression. 

Understanding "Lifting State Up" in React - Example Tutorial


If you have ever worked with React, then you know the importance of state management. The state is managed within the component and decides the component’s behavior. But as the application grows, the state is required to be shared among the different components. For such global state sharing, third-party libraries such as Redux are used.

Apart from managing the state inside a component or using redux for the global state, there is one more way to work with the state. This is called “lifting state up”. In this article, we will discuss what is “lifting state up” in React with the help of an example.