Delete from object by key

Question

I am trying to remove a property from the object by key.

It's very important to notice that I have the key in my variable, and i am unable to do the following:

delete obj.test.a

This is my code (which doesn't work)

var obj = {
 b: 2,
   test: {
      a: 1
   }
}

var abc = 'test.a';

delete obj[abc];

console.log(obj);

How can I acheive deleting obj.test.a without hardcoding, and instead taking the key from variable.

Think you'll need to write a function for this that splits the string on '.' and then moves down the object until the last one and removes it. — Arg0n, Mar 10 '17 at 13:50
You can also "delete" properties this way... `obj.text.a = undefined` — evolutionxbox, Mar 10 '17 at 13:51
Possible dukplictae of [Accessing nested JavaScript objects with string key](http://stackoverflow.com/questions/6491463/accessing-nested-javascript-objects-with-string-key) — Felix Kling, Mar 10 '17 at 14:15

Nenad Vracar · Accepted Answer · 2017-03-10T14:13:49.863

1

You can first split you string to array and then use reduce() to match object you want to delete and delete it.

var obj = {"b":2,"test":{"a":1}}

var abc = 'test.a'.split('.')
abc.reduce(function(r, e, i) {
  if(i == abc.length - 1) delete r[e]
  return r[e]
}, obj)

console.log(obj);

Here is maybe more elegant approach

var obj = {"b":2,"test":{"a":1}}

'test.a'.split('.').reduce(function(r, e, i, arr) {
  return arr[i + 1] ? r[e] : (delete r[e])
}, obj)

console.log(obj);

edited Mar 10 '17 at 14:13

answered Mar 10 '17 at 13:55

Nenad Vracar

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1

You should try it. – Nenad Vracar Mar 10 '17 at 13:56

score 0 · Answer 2 · answered Mar 10 '17 at 13:55

Example explaining my comment:

var obj = {
   test: {
      a: 'hello'
   }
};

function deleteProp(obj, path) {
   var props = path.split('.');
   var currentObj = obj;
   for(var i = 0; i < props.length; i++) {
      var prop = props[i];
      if(i == props.length - 1) {
         delete currentObj[prop];
      } else {
         currentObj = currentObj[prop];
      }
   }
}

deleteProp(obj, 'test.a');
console.log(obj); // { test: {} }

Delete from object by key

2 Answers2