面试专题：如何对对象的部分属性按序访问

编程题：
如下所示，对象有N个属性，需要对其中的key1 - key5属性按序优先显示，其他属性则按原序显示

 // 输入
  const obj = {
  ...
    key10: 'key10',
    key4: 'key4',
    key5: 'key5',
    key2: 'key2',
    key1: 'key1',
    key3: 'key3',
    ...
  }

 // 输出
  const obj = {
   key1: 'key1',
   key2: 'key2',
   key3: 'key3',
   key4: 'key4',
   key5: 'key5',
   key10: 'key10',
   ...
}

实现1: 直接赋值

function sortedObj0(){
	const orderKey = ['key1', 'key2', 'key3', 'key4', 'key5'];
	const sortedDetail = {};
	orderKey.forEach(key => {
		if (obj[key]) {
			sortedDetail[key] = obj[key];
		}
	});

	Object.keys(obj).forEach(key => {
		if (!sortedDetail[key]) {
			sortedDetail[key] = obj[key];
		}
	});

	console.log(sortedDetail)
	return sortedDetail
}

实现2：使用解构语法

function sortedObj1(){
	const {key1, key2, key3, key4, key5, ...rest} = obj;
	const result = {
		key1,
		key2,
		key3,
		key4,
		key5,
		...rest
	}
	console.log(result)
	return result;
}

实现3： 使用数据排序

function sortedObj2() {
	const orderKey = ['key1', 'key2', 'key3', 'key4', 'key5'];

	const orderObjKey = Object.keys(obj).sort((a,b) => {
		let indexA = orderKey.indexOf(a);
		let indexB = orderKey.indexOf(b);

		if (indexA === -1) indexA = Number.MAX_SAFE_INTEGER;
		if (indexB === -1) indexB = Number.MAX_SAFE_INTEGER;

		return indexA - indexB
	})

	const resultObj = {};
	orderObjKey.forEach(key => {
		resultObj[key] = obj[key]
	})

	console.log(resultObj)
	return resultObj;
}