Null safety, reflection, and annotations

Although we have already covered the most common topics that relate to a basic overview of Kotlin, there are a few more topics that have to be touched upon.

This section will introduce the following topics:

• Null safety
• Reflection
• Annotations

Null safety

Kotlin supports a more strict type system when compared to Java, and divides all types into two groups, as follows:

• Nullable
• No-nullable

One of the most popular causes of an app crashing is the NullPointerException. This happens as a result of accessing a member of a null reference. Kotlin provides a mechanism that helps us to avoid this error by using a type system.

The following diagram shows what the class hierarchy looks like...