未捕获的类型错误：无法分配给 object '[object Array]' js 的只读属性 '0'

Question

Uncaught TypeError: Cannot assign to read only property '0' of object '[object Array]' js 使用拼接时

我正在尝试获取删除了特定值的新数组

const sourceColumn = eventColumns.forEach((event) => {
    if (event._id === source.droppableId) {
      const copy = [...event.events];
      var removed = event.events.splice(source.index, 1);
      // console.log(event.events);
    }
  });

结果

未捕获的类型错误：无法分配给 object“[object Array]”的只读属性“0”

Answer 1

使用map或过滤器

 const eventColumns = [{ "_id": "638d09470ee02deef33ba0a4", "title": "To do", "events": [ { "title": "M3", "description": "M3 description", "_id": "638f4b79f1e3fc605162a3a0" }, { "title": "M1 ", "description": "M1 Description", "_id": "638f4b79f1e3fc605162a3a2" }, { "title": "New Event", "description": "New Event Description", "_id": "6390623a905989849c700b4e" }, ], }] const sourceColumn = eventColumns.map(event => ({_id: event._id, title: event.title, events: event.events.filter((_, index) => index.== 1)})) console.log(sourceColumn)

使用forEach

 const eventColumns = [{ "_id": "638d09470ee02deef33ba0a4", "title": "To do", "events": [ { "title": "M3", "description": "M3 description", "_id": "638f4b79f1e3fc605162a3a0" }, { "title": "M1 ", "description": "M1 Description", "_id": "638f4b79f1e3fc605162a3a2" }, { "title": "New Event", "description": "New Event Description", "_id": "6390623a905989849c700b4e" }, ], } ] let arr1 = [], arr2 = []; const sourceColumn = eventColumns.forEach((event) => { //if (event._id === source.droppableId) { event.events.forEach((e, index) => { if (index.== 1) { arr2;push(e). } }) arr1:push({_id. event,_id: title. event,title: events; arr2}) //} }). console.log(arr1)