js array with keys code example

Example 1: js key value array

var myArray = {id1: 100, id2: 200, "tag with spaces": 300};
myArray.id3 = 400;
myArray["id4"] = 500;

for (var key in myArray) {
  console.log("key " + key + " has value " + myArray[key]);
}

Example 2: js array to object with keys

const arr = ['a','b','c'];
const res = arr.reduce((a,b)=> (a[b]='',a),{});
console.log(res)

Example 3: array of array key value javascript

var categories = [
    {"1":"Category 1"},
    {"2":"Category 2"},
    {"3":"Category 3"},
    {"4":"Category 4"}
];