本地存储Javascript中的独立对象
问题描述：
我目前在本地存储中有一个看起来像这样的项目
I currently have an item in local storage which looks like this
"cars":[
{
"Id":7,
"Name":"Audi",
},
{
"Id":8,
"Name":"Ford",
}
我只想检索所有Id并将其存储在字符串中. 在此刻，我正在像这样提取数据:
I want to retrieve all of the Id's only and store them in a string. At the minute I am pulling the data like this:
var cars = "";
cars= localStorage.getItem('cars');
var carArr= new Array();
carArr.push(cars);
我如何才能获得ID
答
localStorage仅支持strings.因此，您必须使用JSON.parse来从字符串中获取cars数组，然后使用array#map来获取所有id.
localStorage only supports strings. So, you have to use JSON.parse to get the cars array from string and then use array#map to get all the ids.
var carsString = localStorage.getItem('cars');
var cars = JSON.parse(carsString);
var ids = cars.map( car => car.Id);
console.log(ids);