In which cases is it optimal to use inline functions in a program?

Inline functions in Kotlin (commonly used in Android development) optimize function calls, especially when working with lambdas.

When to use inline functions:

• If a function takes lambda expressions and is called frequently, inline allows avoiding the creation of additional objects and calls.
• To improve performance in speed-critical areas.
• To implement higher-order functions with the ability to use noinline and crossinline to control lambda behavior.

Example:

inline fun performOperation(operation: () -> Unit) {
    println("Before operation")
    operation()
    println("After operation")
}

performOperation {
    println("Executing operation")
}

Here, the body of operation is inserted directly into the call site, reducing overhead.

However, you should not use inline for large functions, as it will increase the bytecode size.