swift 闭包捕获列表

allanGold2024-03-05 13:50

复制代码

var car = "Benz" 
let closure = { [car] in 
  print("I drive \(car)")
} 
car = "Tesla" 
closure()

因为 clousre 已经申明将 car 复制进去了（[car]），此时clousre 里的 car 是个局部变量，不再与外面的 car有关，所以会打印出"I drive Benz"。此时面试官微微一笑，将题目略作修改如下：

复制代码

var car = "Benz" 
let closure = {
  print("I drive \(car)")
} 
car = "Tesla" 
closure()

此时closure没有申明复制拷贝car，所以clousre用的还是全局的car变量，此时将会打印出 "I drive Tesla"