遍历对象的对象并提取等于特定值的键值？

Question

I am trying to avoid dependencies such as loaddash (_.filter) and use pure javascript.

Basically I have an object of objects, and I need to loop through and filter out all that dont have a parent_id of a specific value.

var filterBy = 50
var obj = {
  256: {
    name: john
    parent_id: 50
  },
  341: {
    name: dwit
    parent_id: 50
  },
  398: {
    name: ryan
    parent_id: 30
  },
  421: {
    name: jack
    parent_id: 50
  }
}

with the result being

var filteredOBJ = {
  256: {
    name: john
    parent_id: 50
  },
  343: {
    name: dwit
    parent_id: 50
  },
  421: {
    name: jack
    parent_id: 50
  }
}

Answer 1

 const result = {};
 for(const [key, val] of Object.entries(obj)) {
    if(val.parent_id === filterBy) {
       result[key] = val;
    }
  }

Just turn what you described into code and you're done.

Answer 2

Here's an implementation of a simple filter in ES6 :

let myObj = {
  256: {
    name: "john",
    parent_id: 50
  },
  341: {
    name: "dwit",
    parent_id: 50
  },
  398: {
    name: "ryan",
    parent_id: 30
  },
  421: {
    name: "jack",
    parent_id: 50
  }
}

let result = {};
Object.entries(myObj).forEach( ([key, value]) => {
  if(key != 398)  // condition over keys 
    result[key] = value;
})
console.log(result);

Answer 3

If you like the loadash approach, but want to use javascript, reduce() on the Object.entries() will give you nice functional approach, although the above forEach solutions probably win for readabilty.

 var filterBy = 50 var obj = {256: {name: 'john',parent_id: 50},341: {name: 'dwit',parent_id: 50},398: {name: 'ryan',parent_id: 30},421: {name: 'jack',parent_id: 50}} let r = Object.entries(obj).reduce((a, [k, v]) => v.parent_id === filterBy ? Object.assign(a, {[k]: v}) : a, {}) console.log(r)