Converting primitive wrapper objects to String
When working with Java programming, there are scenarios where you might need to convert objects of primitive wrapper classes to strings. This process is essential for various reasons, such as…
Accessing ArrayList Elements
To access a single ArrayList element, use ArrayList.get() method. To print all elements, you can use a simple for loop with ArrayList.get() method or use an Iterator object to iterate…
ArrayList NullPointerException
Java’s ArrayList is a great Collection that frees us from IndexOutOfBound, one type limitation, and NullPointerException issues while providing several value-added methods. Naturally, you would be shocked if you encounter…
Creating custom exceptions in Java
Java allows programmers to create their own Exceptions. To create and exception, you should inherit from the exception closest to what you wish to create. Following is a generic example…
Replacing and removing subtrings in Java
Java’s replaceString function is very handy for string and substring modifications. output First part of the all occurrences of a with e Second part remove all occurrences of the character…
Splitting strings in Java
Java’s split function packs a powerful punch. You can use it to split string on characters, symbols, substrings, a collection of symbols, or even regular expressions. output First part of…
ArrayList and Iterator Example
This example shows how to use an iterator with ArrayList. Iterator can be used with other collections. output Note that if you are using Java 5 or above, you will…
Generating Random Numbers in Java
In programming, often we need to generate random numbers. All major languages provide functionality to generate pseudo-random numbers. In Java, this functionality is provided by java.util.Random. See example below: output…
How to install npm on Ubuntu
Update your repository if you haven’t done so in a long time Install nodejs Install npm Check if npm installed correctly You shouldn’t get any error messages and the second…
Installing Moodle on Linux
First of all make sure that you have Apache, MySQL (or PostgreSQL), and PHP installed and configured on your system. On Ubuntu, you would type the following to install these…