save only keys in dictionary javascript code example

Example 1: react dictionary key value avec 2 variable

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

Example 2: javascript add to a dictionary

var d = {}

for (var i in input) {
    var datum = input[i];
    d[datum.key] = datum.val
}