Question

我需要帮助如何做到这一点，我有todos，如果它的ID在参数中，我想要更新数组中的todos isComplete属性，如下代码：

const todos = [{id: 1, text:"one",isComplete:false},{id:2,text:"two",isComplete:false},{id:3,text:"three",isComplete:false}];

const myArgs = [2,3];
const completeAllTodos = todos.filter(todoItem.id =>  myArgs.includes(todoItem.id)); 
completeAllTodos.map( todoItem => todoItem.isComplete = true);

在completeAllTodos上我想返回参数数组中存在ID的todos对象，然后将completeAllTodos isComplete属性更新为true。我也想异步做，但我是javascript的新手。我一直在想如何做好几个小时，但我不能让我的大脑做我想做的事。帮助

Answer 1

如果您只想将isCompletes设置为true：

const todos = [{id: 1, text:"one",isComplete:false},{id:2,text:"two",isComplete:false},{id:3,text:"three",isComplete:false}];
myArgs = [2,3];
todos.forEach(el=>myArgs.indexOf(el.id)+1?el.isComplete=true:0);

如果你也想要这个元素：

const todos = [{id: 1, text:"one",isComplete:false},{id:2,text:"two",isComplete:false},{id:3,text:"three",isComplete:false}];
myArgs = [2,3];
var result=todos.filter(el=>myArgs.indexOf(el.id)+1).map(el=>!(el.isComplete=true)||el);

如果你想要两个：

const todos = [{id: 1, text:"one",isComplete:false},{id:2,text:"two",isComplete:false},{id:3,text:"three",isComplete:false}];
myArgs = [2,3];
var results=todos.reduce((arr,el)=>myArgs.indexOf(el.id)+1?(el.isComplete=true,arr.push(el),arr):arr);

http://jsbin.com/wopexiwime/edit?console

如果你真的需要一个异步实现（我不这么认为）：

function forEach(arr,call,i=0){
   if(i>=arr.length){
      return;
   }
   call(arr[i],i);
   setTimeout(forEach,0,arr,call,i+1);
}

function filter(arr,call,finalcall,i=0,res=[]){
   if(i>=arr.length){
      return finalcall(res);
   }
   if(call(arr[i],i)) res.push(arr[i]);
   setTimeout(filter,0,arr,call,finalcall,i+1,res);
}

function map(arr,call,finalcall,i=0,res=[]){
   if(i>=arr.length){
      return finalcall(res);
   }
   res.push(call(arr[i],i));
   setTimeout(map,0,arr,call,finalcall,i+1,res);
}

map([1,2,3,4],(e,i)=>e+i,console.log);

Answer 2

这是单向的。

const todos = [{
  id: 1,
  text: "one",
  isComplete: false
}, {
  id: 2,
  text: "two",
  isComplete: false
}, {
  id: 3,
  text: "three",
  isComplete: false
}];

const myArgs = [2, 3];
const completeAllTodos = todos
  .filter(todo => {
    return myArgs.includes(todo.id)
  })
  .map(todo => {
    todo.isComplete = true
    return todo
  });
console.log(completeAllTodos)

Answer 3

在过滤器循环块中完成所有操作：

const todos = [{
  id: 1,
  text: "one",
  isComplete: false
}, {
  id: 2,
  text: "two",
  isComplete: false
}, {
  id: 3,
  text: "three",
  isComplete: false
}];

const args = [2, 3];
const completedTodos = todos.filter(item => args.includes(item.id) && (item.isComplete=true));

console.log(completedTodos);

如何检查数组中的对象是否在参数ID中存在ID属性？

3 个答案: