如何从javascript中的内部JSON数组创建具有某些属性的数组

Question

So I have :

list = 
    {
      id: 1,
      arr: [
        {index : 1 , description: "lol" , author: "Arthur"},
        {index : 2 , description: "sdadsa" , author: "Bob"},
        {index : 3 , description: "loasd" , author: "Mackenzie"}
      ]
    }

and I want to create an array only with description and author property from the arr array.

I tried var a = {l : list.arr.map(x => {x.description,x.author})} . But all items from the array are undefined .

Answer 1

Another approach would be to use the rest parameter . This way you can remove the index and keep everything else intact.

 var list = { id: 1, arr: [ { index: 1, description: "lol", author: "Arthur" }, { index: 2, description: "sdadsa", author: "Bob" }, { index: 3, description: "loasd", author: "Mackenzie" }, ], }; var a = list.arr.map(({index, ...rest}) => rest); console.log(a);

Answer 2

You almost finish, you should define the key in your return object in the map funciton.

 var list = { id: 1, arr: [ { index: 1, description: "lol", author: "Arthur" }, { index: 2, description: "sdadsa", author: "Bob" }, { index: 3, description: "loasd", author: "Mackenzie" }, ], }; var a = list.arr.map(x => ({ description: x.description, author: x.author, })); console.log(a);

Answer 3

 list = { id: 1, arr: [{ index: 1, description: "lol", author: "Arthur" }, { index: 2, description: "sdadsa", author: "Bob" }, { index: 3, description: "loasd", author: "Mackenzie" } ] } var a = { l: list.arr.map(x => ({ "description": x.description, "author": x.author })) } console.log(a);

Answer 4

You just forget to define keys in return object.

 var list = { id: 1, arr: [ { index: 1, description: "lol", author: "Arthur" }, { index: 2, description: "sdadsa", author: "Bob" }, { index: 3, description: "loasd", author: "Mackenzie" }, ], }; var a = l.arr.map(x => ({ description: x.description, author: x.author, }));