javascript - 如果在对象中找到值，则返回键

Question

有一个像这样的对象:

var animals = { "dog": ["black", "red", "green"],
                 "cat": ["pink", "red", "white"],
                 "bird": ["green", "grey", "yellow"]};

我想取回具有特定颜色的动物的名称，例如 "red" 我想返回一个包含 ["dog", "cat"的数组];尝试这样做，但我只返回 Array(0) 或 Array(1)

function findColor(animals, color) {

  var result = [];
  if (Object.values(animals).indexOf(color) > -1) {
    result.push(color);
  }

  return result;
}

console.log(findColor(animals, "red"));

Answer 1

您可以简单地使用 Object.keys 和 filter

var animals = {
  "dog": ["black", "red", "green"],
  "cat": ["pink", "red", "white"],
  "bird": ["green", "grey", "yellow"]
};

function findColor(animals, color) {
  return Object.keys(animals).filter(key=>animals[key].includes(color))
}

console.log(findColor(animals, 'red'));

---

Why my code is not working ?

indexOf 使用严格比较，Object.values(animals) 返回一个二维数组，而您正试图将它与字符串值匹配，您需要做的是遍历键并在二维数组的子数组上使用 indexOf

var animals = {"dog": ["black", "red", "green"],"cat": ["pink", "red", "white"],"bird": ["green", "grey", "yellow"]};

function findColor(animals, color) {
  var result = [];
  Object.keys(animals).forEach(v => {
    if (animals[v].indexOf(color) > -1) {
      result.push(v)
    }
  })
  return result;
}

console.log(findColor(animals, "red"));