Question

请考虑以下数据：

const state = {
  tasks: {
    'ID1': {
      name: "Go to shop",
      completed: false,
    },
    'ID2': {
      name: "Get bananas",
      completed: true,
    },
    'ID3': {
      name: "Get apples",
      completed: false,
    }
  }
}

要仅检索将completed设置为true的任务，可以使用以下代码：

function getCompletedTasks(state) {
  let tasks = {}

  Object.keys(state.tasks).forEach((key) => {
    let task = state.tasks[key]

    if (task.completed) tasks[key] = task
  })

  return tasks
}

我想知道是否有比通过array手动创建新的let tasks = {}更好的方法？我看过map，但我不确定这是否有帮助。我是新手，只是想了解是否有更清洁的更好方法。

Answer 1

您可以使用Object.entries获取条目数组，根据值的completed属性是否为真对它进行过滤，然后将其转换为带有Object.fromEntries的对象：

const state = {
  tasks: {
    'ID1': {
      name: "Go to shop",
      completed: false,
    },
    'ID2': {
      name: "Get bananas",
      completed: true,
    },
    'ID3': {
      name: "Get apples",
      completed: false,
    }
  }
}

function getCompletedTasks(state) {
  return Object.fromEntries(
    Object.entries(state.tasks).filter(([, val]) => val.completed)
  );
}

console.log(getCompletedTasks(state));

根据值过滤嵌套的对象属性

1 个答案: