How can I add a key/value pair to a Javascript object when the value is empty?

Question

I need to add a new key to my Javascript object, obj. Using the method below works fine as long as I have a value to go with the key.

The method below inserts the actual characters "" into the value position. I want to add the new item "key3", but I want it to now appear in obj as "key3":{} .

Here is my code:

  //1.adding key/value pair var obj ={ "key1":{}, "key2":{} }; obj["key3"] = "test"; //obj now looks like: obj ={ "key1":{}, "key2":{}, "key3": test }; //2.adding key/value pair with empty value var obj ={ "key1":{}, "key2":{} }; obj["key3"] = ""; //obj now looks like: obj ={ "key1":{}, "key2":{}, "key3": "" }; //but I want obj to look like: var obj ={ "key1":{}, "key2":{}, "key3":{} }; 

Answer 1

Assign an object instead of a string.

var obj ={
    "key1":{},
    "key2":{}
};



obj["key3"] = {};



//////////////////////////////////////////////////////////////
New Object:

var obj ={
    "key1":{},
    "key2":{},
    "key3":{}
};

Answer 2

A functional, non-mutative approach with ES6 could look something like this:

const initialObject = {
    key1:{},
    key2:{}
};

const keysToAdd = {
  key3: {}
};

const updatedObject = Object.assign({}, initialObject, keysToAdd);

console.log(updatedObject);

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