Javascript闭包和变量
有谁能告诉我,为什么当我得到变量myBrand directy时,结果是默认值? 我只是在玩闭包,试图对返回做一些不同的事情,基本上没有把它放进去,这给了我一开始的默认值Javascript闭包和变量,javascript,variables,scope,closures,Javascript,Variables,Scope,Closures,有谁能告诉我,为什么当我得到变量myBrand directy时,结果是默认值? 我只是在玩闭包,试图对返回做一些不同的事情,基本上没有把它放进去,这给了我一开始的默认值 const car = ()=>{ let myBrand = 'generic' //default value function printbrand(){console.log(myBrand)} return{ setBrand: (newBrand)=>{myBrand = ne
const car = ()=>{
let myBrand = 'generic' //default value
function printbrand(){console.log(myBrand)}
return{
setBrand: (newBrand)=>{myBrand = newBrand},
getBrand: ()=>{return myBrand},
getBrandSimple: myBrand,
usePrinter: ()=> {return printbrand()},
}
}
var myCar = car()
myCar.setBrand('tesla')
console.log(`Brand with direct = ${myCar.getBrandSimple}`)
//Output
// Brand with direct = generic
console.log(`Brand with function = ${myCar.getBrand()}`);
//Output
// Brand with function = tesla
console.log(`Brand with printer = `);
myCar.usePrinter()
//Output
// Brand with printer =
// tesla
console.log(`Brand with direct = ${myCar.getBrandSimple}`)
//Output
// Brand with direct = generic
getBrandSimple
包含创建对象时myBrand
值的副本
它不包含对变量的引用,因此当您更改变量的值时,不会更改getBrandSimple
的值