An array of objects are a list of object enclosed in [], each object holds key and value pairs. How do I connect these two faces together? In this post, I will show how to retrieve the following information from a Table Cell that was clicked. In this post, I explore a handful of TypeScript features to create Union types from a Bijective Map and use them to restrict what value (not just type) the keys can take when sending data object to Google Analytics.. As a recap, two sets are described as bijective if every value of one set maps to a value of the other set and vice versa. For example, if a subclass of Array inherits the from() method, the inherited from() method will return new instances of the subclass instead of Array instances. To summarize, We have learned multiple ways to convert JSON objects to/from JSOn in typescript and javascript. Content available under a Creative Commons license. It also makes it possible for the IDE to flag errors while typing and provides IntelliSense with auto-completion. It should return an array containing new elements of the new array, or a single non-array value to be added to the new array. Product could only represent success. But here TypeScript's "index signatures" provide exactly this for plain JavaScript objects and even allow a name for keys: This can be used almost like a Map (with different syntax, of course) and it directly converts to JSON even when nested. type studentScore= { [name: string]: number }; type studentScore = Record