从一个对象数组中，如何获取一个对象的值，该对象的值与一个变量匹配？

Question

假设你有一个对象数组。

let dogs = [
  { 
    colour: "blue",
    breed: "poodle"
  },
  { 
    colour: "yellow",
    breed: "poodle"
  },
  { 
    colour: "red",
    breed: "laborator"
  }
];

按品种匹配时如何获得颜色？

我试过了：

let myFavouriteColour = dogs.find(dog => {
   if (dog.breed === "laborator") return dog.colour
});

这会返回一个符合上述条件的对象；我只希望它返回 colour 属性中的值。

Answer 1

一旦你.find匹配，返回true（或者只返回一个相等测试），然后访问.find之外匹配对象的属性：

let dogs = [
  { 
    colour: "blue",
    breed: "poodle"
  },
  { 
    colour: "yellow",
    breed: "poodle"
  },
  { 
    colour: "red",
    breed: "laborator"
  }
];

const laborator = dogs.find(dog => dog.breed === "laborator");
if (laborator) {
  const myFavouriteColour = laborator.colour;
  console.log(myFavouriteColour);
}

Answer 2

Array.find() 是 JavaScript 中的一个内置函数，用于获取数组中第一个元素的对象（或值，如果它是一个值数组）满足提供的条件。您可以访问返回结果的属性。

let dogs = [
  { 
    colour: "blue",
    breed: "poodle"
  },
  { 
    colour: "yellow",
    breed: "poodle"
  },
  { 
    colour: "red",
    breed: "laborator"
  }
];

let myFavouriteColour = dogs.find(dog => dog.breed === "laborator").colour;
console.log(myFavouriteColour);