Javascript Get length of list of items in object?

1: ES5.1 solution use Object.keys - returns an array of a given object's own enumerable properties

var obj = {
  0: 8,
  1: 9,
  2: 10
}
console.log(Object.keys(obj).length)

2: Pre-ES5 Solution: use for..in and hasOwn

var obj = {
  0: 8,
  1: 9,
  2: 10
};

var propsLength = 0;
for (prop in obj) {
  if (obj.hasOwnProperty(prop)) {
    propsLength = propsLength + 1;
  }
}
console.log(propsLength);

3: Library Solution: Use lodash/underscore Convert it to an array, and query its length, if you need a pure js solution, we can look into how toArray works.

console.log(_.toArray({
  0: 8,
  1: 9,
  2: 10
}).length)

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>

You could get the keys using Object.keys, which returns an array of the keys:

Example

var obj = {0: 8, 1: 9, 2: 10};

var keys = Object.keys(obj);

var len = keys.length

You can use Object.keys(). It returns an array of the keys of an object.

var myObject = {0: 8, 1: 9, 2: 10};
console.log(Object.keys(myObject).length)