Question

具有如下对象：

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

我想找回具有某种颜色的动物的名字，例如对于"red"，我想返回一个包含["dog", "cat"]的数组；试图做到这一点，但我只能找回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'));

为什么我的代码不起作用？

indexOf使用严格的比较，Object.values（animals）返回2d数组，并且您尝试将其与字符串值匹配，您需要执行的操作是遍历键并在2d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"));

Answer 2

您可以使用Object.keys然后对数组进行迭代，然后根据条件进行检查：

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

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

}

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

如果在对象内找到值，则返回键

2 个答案: