How can I access and process nested objects, arrays, or JSON?

Preliminaries JavaScript has only one data type which can contain multiple values: Object. An Array is a special form of object. (Plain) Objects have the form {key: value, key: value, ...} Arrays have the form [value, value, ...] Both arrays and objects expose a key -> value structure. Keys in an array must be numeric, whereas any string can be used as key in objects. The key-value pairs are also