Kotin Scope Function Examples

scope-functions.kt

fun main() {
    println("--- let ---")
    //yo().let { println(this) }                      // compile error
    yo().let { println(it) }                          // AAA(greeting=hello)
    println(yo().let { it.greeting + " world" })      // hello world

    println("\n--- run ---")
    yo().run { println(this) }                        // AAA(greeting=hello)
    yo().run { println(greeting.length) }             // 5
    println(yo().run { "high " + greeting.length })   // high 5

    println("\n--- also ---")
    //yo().also { println(this) }                     // compile error
    yo().also { println(it) }                         // AAA(greeting=hello)
    println(yo().also { it.greeting + " world" })     // AAA(greeting=hello)

    println("\n--- apply ---")
    yo().apply { println(this) }                      // AAA(greeting=hello)
    yo().apply { println(greeting.length) }           // 5
    println(yo().apply { "high " + greeting.length }) // AAA(greeting=hello)

    println("\n--- with ---")
    with(yo()) { println(this) }                      // AAA(greeting=hello)
    with(yo()) { println(greeting.length) }           // 5
    println(with(yo()) { "high " + greeting.length }) // high 5

}

fun yo(): AAA {
    return AAA(greeting = "hello")
}

data class AAA(val greeting: String)