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in Technique[技术] by (71.8m points)

关于这道面试题,我的理解是否正确

function func() {
  let i = 0
  return () => {
    i++
    return i
  }
}
const func1 = func()
const func2 = func()

func1()
func2()
func1()
func2()

func1和func2分别创建了func()的对象

变量i未被销毁,所以结果为

1、1、2、2

请问这样理解是够正确,不正确还望纠正下,谢谢


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Welcome To Ask or Share your Answers For Others

1 Answer

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by (71.8m points)
  1. func函数执行后返回的一个闭包函数,这个函数的多次调用将更新i的值;
  2. 而每次func函数调用返回的函数的作用域对象/函数运行的上下文是相互独立的
function func() {
  let i = 0;
  //返回一个闭包函数
  return () => {
    i++;
    return i;
  }
}
const func1 = func();//func1指向闭包函数
const func2 = func();//func2指向闭包函数,和func1是2个不同的函数对象


func1();//i=1;
func2();//i=1;
func1();// i=2;
func2();//i =2

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
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