Ada*_*cha 4 javascript destructuring optional-chaining nullish-coalescing
Currently I am using below code for destructuring:
const myObj1 = {name: 'Abc'}
const {name} = myObj1
console.log(name)
const myObj2 = null
const {name2} = myObj2 // this will give errorRun Code Online (Sandbox Code Playgroud)
Now, since we have optional chaining, I can do this:
const myObj = {name: 'Abc'}
const {name} = myObj
console.log(name) // 'Abc'
const myObj2 = null
const name2 = myObj2?.myObj2
console.log(name2) // undefinedRun Code Online (Sandbox Code Playgroud)
是否有更好的方法或安全的方法来使用无效合并或可选链接进行解构?
const name2 = myObj2?.myObj2 - 这不是解构。
myObj2?.myObj2将返回undefined您分配给的内容name2。
你可以简单地做
const myObj2 = null;
const { name2 } = { ...myObj2 };
console.log(name2); // undefinedRun Code Online (Sandbox Code Playgroud)
如果你想使用空合并运算符,那么你应该使用它,如下所示:
const myObj2 = null
const {name2} = myObj2 ?? {};
console.log(name2) // undefinedRun Code Online (Sandbox Code Playgroud)
如果myObj2为空或未定义,nullish 合并运算符将返回右侧的操作数,否则它将返回左侧的操作数,在您的情况下为myObj2.