对比两个对象数组取被删除的和新增的数组

//原数据
let oldArr = [{faqId: 1, faqName: null}, {faqId: 2, faqName: null}, {faqId: 3, faqName: null}, {faqId: 4, faqName: null},{faqId: 5, faqName: null}]

//新增删除过的数据的数据
let newArr =[{faqId: 2, faqName: null},{faqId: 4, faqName: null},{faqId: 6, faqName: null},{faqId: 8, faqName: null}]

let NewIdArr = newArr.map((e) => e.faqId); 
let oldIdArr = oldArr.map((e) => e.faqId); 

          let addIdArr = NewIdArr.filter((i) => {
            return oldIdArr.indexOf(i) === -1;
          }); //最后添加的数据faqId
          let delIdArr = oldIdArr.filter((i) => {
            return NewIdArr.indexOf(i) === -1;
          }); //最后删除的数据faqId
          let addFaqList = [];
　　　　　　//根据id返回添加的数组对象，删除同理
          this.rowSelection.selectedRows.forEach((e) => {
            addIdArr.forEach((ele) => {
              if (e.faqId === ele) {
                addFaqList.push(e);
              }
            });
          });

 当然了这是手写的方法，loadsh里面有相关的方法，可以去看看

https://www.lodashjs.com/docs/lodash.difference