Javascript: count number of attributes of an Object

var foo = {"key1": "value1", "key2": "value2", "key3": "value3"};
var myObjectPropertiesCount = 0;
         
 for (var myObjectElement in myObject){
      myObjectPropertiesCount++;
 }

console.log(myObjectPropertiesCount);//3

Resource:
http://stackoverflow.com/questions/1345939/how-do-i-count-a-javascript-objects-attributes