How to create dictionary and add key–value pairs dynamically?

Question

From post:

Sending a JSON array to be received as a Dictionary

I’m trying to do this same thing as that post. The only issue is that I d

Answer 1

var dictionary = {};//create new object
dictionary["key1"] = value1;//set key1
var key1 = dictionary["key1"];//get key1

Answer 2

In ES6 you can do this:

let cake = '                                                                    

                                                        
            

Answer 3

I happened to walk across this question looking for something similar. It gave me enough info to run a test to get the answer I wanted. So if anyone else wants to know how to dynamically add to or lookup a {key: 'value'} pair in a JavaScript object, this test should tell you all you might need to know.

var dictionary = {initialkey: 'initialValue'};
var key = 'something';
var key2 =  'somethingElse';
var value = 'value1';
var value2 = 'value2';
var keyInitial = 'initialkey';

console.log(dictionary[keyInitial]);

dictionary[key] =value;
dictionary[key2] = value2;
console.log(dictionary);

output

initialValue
{ initialkey: 'initialValue',
  something: 'value1',
  somethingElse: 'value2' }

Answer 4

how about the one liner for creating a key value pair?

let result = { ["foo"]: "some value" };

and some iterator function like reduce to dynamically convert an array to a dictionary

var options = [
  { key: "foo", value: 1 },
  { key: "bar", value: {id: 2, name: "two"} },
  { key: "baz", value: {["active"]: true} },
];

var result = options.reduce((accumulator, current) => {
  accumulator[current.key] = current.value;
  return accumulator;
}, {});

console.log(result);

Answer 5

You could create a class Dictionary so you can interact with the Dictionary list easily:

class Dictionary {
  constructor() {
    this.items = {};
  }
  has(key) {
    return key in this.items;
  }
  set(key,value) {
    this.items[key] = value;
  }
  delete(key) {
    if( this.has(key) ){
      delete this.items[key]
      return true;
    }
    return false;
  }
}

var d = new Dictionary();
d.set(1, "value1")
d.set(2, "value2")
d.set(3, "value3")
console.log(d.has(2));
d.delete(2);
console.log(d.has(2));

Answer 6

You can use maps with Map, like this:

var sayings = new Map();
sayings.set('dog', 'woof');
sayings.set('cat', 'meow');