Ramda：通过嵌套键值查找对象键

Question

ramda有什么函数可以通过嵌套键值查找键吗？我找到了一种在数组中查找对象的方法，但这无济于事。我需要这样的东西：

const obj = {
  addCompany: {
    mutationId: '1'
  },
  addUser: {
    mutationId: '2'
  },
  addCompany: {
    mutationId: '3'
  }
}
const findByMutationId = R.???
findByMutationId('2', obj) // returns addUser

Answer 1

不确定 ramda，但如果纯 js 中的单行代码对你有好处，那么下面的方法就可以了

const obj = {
    addCompany: {
        mutationId: '1'
    },
    addUser: {
        mutationId: '2'
    }
};

let found = Object.keys(obj).find(e => obj[e].mutationId === '2');
console.log(found);

Answer 2

如果你要使用它，那么你可能需要填充条目，如果你需要键和值，这很好

const obj = {
  addCompany: {
    mutationId: '1'
  },
  addUser: {
    mutationId: '2'
  },
  addCompany: {
    mutationId: '3'
  }
}

let [key, val] = Object.entries(obj).find(obj => obj[1].mutationId == '2')

console.log(key)
console.log(val)

Answer 3

find 结合 propEq 和 keys 应该有效

const obj = {
  addCompany: {
    mutationId: '1'
  },
  addUser: {
    mutationId: '2'
  },
  addCompany2: {
    mutationId: '3'
  }
}
const findByMutationId = id => obj => R.find(
  R.o(R.propEq('mutationId', id), R.flip(R.prop)(obj)),
  R.keys(obj)
)

console.log(findByMutationId('2')(obj))

<script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.24.1/ramda.min.js"></script>

Pointfree 版本 lulz

const obj = {
  addUser: {
    mutationId: '2'
  },
  addCompany: {
    mutationId: '3'
  }
}

const findByMutationId = R.compose(
  R.o(R.head),
  R.o(R.__, R.toPairs),
  R.find,
  R.o(R.__, R.nth(1)),
  R.propEq('mutationId')
)

console.log(findByMutationId('2')(obj))

const findByMutationId2 = R.compose(
  R.ap(R.__, R.keys),
  R.o(R.find),
  R.o(R.__, R.flip(R.prop)),
  R.o,
  R.propEq('mutationId')
)

console.log(findByMutationId2('3')(obj))

<script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.24.1/ramda.min.js"></script>

Ramda：通过嵌套键值查找对象键

Ramda: find object key by nested key value

javascript

functional-programming

ramda.js