如何结合ES6箭头函数使用filter()筛选程序员职业对象？

Hey there! Let's break down what's going wrong with your current code and get it working correctly.

The Issue with Your Current Code #

Your jobs array is filled with objects, not strings. When you write person === "programmer", you're trying to compare an object (like {receptionist: "James"}) directly to a string — which will always return false. That's why your solution array ends up empty!

Fixed Solutions #

Since each object in your array has a single job as its key, here are a few straightforward ways to filter for the programmer:

1. Check if the object has the "programmer" key using in

var jobs = [{receptionist: "James"}, {programmer: "Steve"}, {designer: "Alicia"}];
var solution = jobs.filter(person => "programmer" in person);

This checks if the person object contains the programmer property (including properties inherited from the prototype chain).

2. Use Object.hasOwn() (recommended over in for strict property checks)

var solution = jobs.filter(person => Object.hasOwn(person, "programmer"));

Object.hasOwn() only checks properties directly on the object itself, avoiding any prototype chain surprises.

3. Check via object keys
   If you prefer to explicitly look at the keys of each object:

var solution = jobs.filter(person => Object.keys(person).includes("programmer"));

Object.keys(person) returns an array of the object's keys, and we check if that array includes "programmer".

All of these will give you the expected result: [{programmer: "Steve"}]

Bonus: A More Scalable Data Structure #

If you can adjust your data to use consistent keys (which is more common and easier to maintain), the code becomes even cleaner:

var jobs = [
  {role: "receptionist", name: "James"},
  {role: "programmer", name: "Steve"},
  {role: "designer", name: "Alicia"}
];
var solution = jobs.filter(person => person.role === "programmer");

This makes filtering, mapping, and manipulating the data much more intuitive down the line.

内容的提问来源于stack exchange，提问作者PBandJ333