Kotlin and Java

Difference between var and val in Kotlin

var is used for mutable variables, while val is used for immutable (read-only) variables.

What is the lateinit modifier?

lateinit var allows us to declare a mutable, non-nullable variable without initializing it at the point of declaration. It throws an UninitializedPropertyAccessException if accessed before being initialized.

Is lateinit thread-safe?

No, lateinit is not thread-safe by default. If multiple threads access a lateinit variable before it is properly initialized, it can lead to undefined behavior or exceptions.

What is lazy in Kotlin?

lazy is a property delegate for immutable variables that computes its value only on first access. It is thread-safe by default.

When to use lazy

lazy should be used when an immutable variable needs to be initialized only when it is first accessed, improving performance by avoiding unnecessary computation or deferring it.