But I couldn’t resist the temptation to put in a null reference, simply because it was so easy to implement. My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). It was the invention of the null reference in 1965. Tony Hoare, the inventor of the null reference apologized in 2009 and denotes this kind of errors as his billion-dollar mistake. It’s by far the most prevalent kind of error in Java and many other programming languages as well. But also intermediate and expert programmers get around this error every now and then. In the next tutorial we will discuss about regular expression in Kotlin.How to prevent the famous NullPointerException in Java? This is one of the key questions every Java beginner will ask sooner or later. Null safety is an important feature of Kotlin and it saves us from Null pointer exception. In this tutorial we discussed about Null safety in Kotlin. So, the !! operator should be avoided as much as possible. Let us see a small example in Java where NullPointerException occurs: public class Student ") // Throws NullPointerException If we try to use this variable then we will get NullPointerException or NPE.
In programming world when a variable doesn't refer to anything then it is considered as null.
In this tutorial we will discuss about one of the most important features of Kotlin: Null Safety.
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