Kotlin Coding Standards

Level 1: Quick Reference

Null Safety Cheat Sheet

// Safe Call (?.) - Returns null if receiver is null
val length = user?.name?.length

// Elvis Operator (?:) - Provides default value
val name = user?.name ?: "Unknown"

// Not-Null Assertion (!!) - Throws NPE if null (avoid!)
val length = user!!.name!!.length

// Safe Cast (as?) - Returns null on cast failure
val employee = person as? Employee