BootSelf
Check my readiness
kotlin

Nullable and non-nullable types

1 role need it, 1 as coreUsually level 3: WorkingLesson available

Where it sits

Learn first

If expressionTaming exceptions

This skill

Nullable and non-nullable types

Leads to

Avoiding NPEs. Null safety

Jobs that need it

What level 3 (Working) means

Uses it independently on the job. Level 4 (Strong): handles hard cases, reviews others.

Start learning

Nullable and non-nullable types

Data types

about 11 min10 parts

Open the lesson

Find out where you stand

A free check, then a route that starts at your level.

Check my readiness

Learned alongside it

Abstract classesAdditional librariesAggregate operations on collectionsAggregate operations on collections: part 2AndroidAndroid CoreAndroid JetpackAndroid studio basics

Nullable and non-nullable types: common questions

What is Nullable and non-nullable types?

Nullable and non-nullable types is a skill in kotlin, needed by 1 role on BootSelf.

Which jobs need Nullable and non-nullable types?

Android Developer. Most ask for level 3 (Working): uses it independently on the job.

What should I learn before Nullable and non-nullable types?

If expression, Taming exceptions.

How long does it take to learn Nullable and non-nullable types?

The starting lesson, Nullable and non-nullable types, takes about 11 minutes. Reaching the level a job asks for takes practice on top: BootSelf measures where you are and plans the rest.

How do I practise Nullable and non-nullable types?

Check your readiness for free, then BootSelf builds a route and short daily learning loops: a little theory, checks on what you get wrong, then a small program.