### `also` **上下文對象**作為 lambda 表達式的參數（`it`）來訪問。 **返回值**是上下文對象本身。 `also` 對于執行一些將上下文對象作為參數的操作很有用。 Use `also` for actions that need a reference rather to the object than to its properties and functions, or when you don't want to shadow `this` reference from an outer scope. 當你在代碼中看到 `also` 時，可以將其理解為“*并且用該對象執行以下操作*”。 ```kotlin fun main() { //sampleStart val numbers = mutableListOf("one", "two", "three") numbers .also { println("The list elements before adding new one: $it") } .add("four") //sampleEnd } ```