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.

Answer 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); 

Answer 2

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: {} }

Answer 3

delete obj.test.a works for me: