如果对象键在打字稿中是动态的，如何获取值？

Question

I have an array of object.structure is like that.

animal = [{"cow":{"leg":4,"eye":2}},{"monkey":{"leg":2,"eye":2}}]

here first key is dynamic like cow and monkey

so my question is how can i access the key leg if first key is dynamic

Answer 1

If you are sure that each object within the array as only 1 property (which would be the type of animal), you can do something like this.

 animals = [{"cow":{"leg":4,"eye":2}},{"monkey":{"leg":2,"eye":2}}]; for (let animal of animals) { let propName = Object.keys(animal)[0]; let result = animal[propName]; console.log(result); // <- Do what you want with it } 

Answer 2

这将为您提供一系列具有每只动物内容的对象。

animals.map(animal => animal[Object.keys(animal)[0]]);

Answer 3

Maybe convert it into a "non-dynamic-key" object?

 const animal = [{"cow":{"leg":4,"eye":2}},{"monkey":{"leg":2,"eye":2}}] const newanimal = animal.map(obj => { const keys = Object.keys(obj) return keys.map(key => ({ key, value: obj[key] })) }).flat(Math.Infinity) console.log(newanimal) 

Answer 4

1) Find an animal with that key

2) Return it with [animal]

3) Use it as you would ( .leg )

const animals = [{ cow: { leg: 4, eye: 2 } }, { monkey: { leg: 2, eye: 2 } }];

const animal = 'cow';
const leg = animals.find(a => !!a[animal])[animal].leg;

Answer 5

You can use map & Object.keys . map will return a new array. Object.keys is use to get all the keys inside each of the object in animal array.Then this line elem[getKeys].leg will retrieve the value of the leg key

 let animal = [{ "cow": { "leg": 4, "eye": 2 } }, { "monkey": { "leg": 2, "eye": 2 } }]; let legVal = animal.map((elem) => { let getKeys = Object.keys(elem)[0]; return elem[getKeys].leg }) console.log(legVal) 

Answer 6

You can use the newly added Object.entries , which make the most sense imo.

Thus for your data you have:

const animal = ...
for (a of animal) {
    const [animalName, animalDesc] = Object.entries(a)[0]; // assumes there is only one
}