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# takeIf

```kotlin
// (T) -> it으로 접근가능
inline fun <T> T.takeIf(predicate: (T) -> Boolean)
: T? = if (predicate(this)) this else null

// T로 부터 takeIf 를 사용가능 반환값 T는 Nullable
// Boolean 을 반환하는 predicate 함수를 하나 받아서 그 함수의 반환값이 true 면 자기 자신을 반환하고
// false 면 null을 반환한다.
// 보통 체크하는것을 predicate 라는 이름으로 많이 사용한다. 
```

```kotlin
// false 인 경우
val ari = person.takeIf { it.name == "ari" }
println(ari) // null

// true 인 경
val gold = person.takeIf { it.name == "gold" }
println(gold) // Person(name=gold, age=18)

val default = person.takeIf { it.name == "ari" } ?: Person("ari", 24)
println(default) //Person(name=ari, age=24)
```


---

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