То есть количество ключей.
function objectSize(the_object) ( /* function to validate the existence of each key in the object to get the number of valid keys. */ var object_size = 0; for (key in the_object)( if (the_object.hasOwnProperty(key)) ( object_size++; ) ) return object_size; )использование
// Arbitrary object var something = ( dog: "cat", cat: "dog" ) console.log(objectSize(something)); // Logs: 2