Scope Functions in Kotlin

// let - it as argument, returns result
val result = "Hello".let {
    println("Original: $it")
    it.uppercase()
}  // HELLO

// Null safety with let
val nullableString: String? = "Kotlin"
nullableString?.let {
    println("Length: ${it.length}")
}

// run - this as receiver, returns result
val formatted = "hello".run {
    println("Original: $this")
    uppercase()
}  // HELLO

// with - non-extension, returns result
val numbers = mutableListOf(1, 2, 3)
val sum = with(numbers) {
    add(4)
    add(5)
    sum()
}

// apply - this as receiver, returns receiver
val person = Person().apply {
    name = "Alice"
    age = 30
    email = "alice@example.com"
}

// also - it as argument, returns receiver
val list = mutableListOf(1, 2, 3).also {
    println("Adding items to list: $it")
    it.add(4)
}