Boolean in JavaScript and TypeScript
10 September 2019
boolean is a fun primitive data type in JavaScript. In TypeScript, it allows for a total of four values
Wait, four?
Web ops, performance and front-end
boolean is a fun primitive data type in JavaScript. In TypeScript, it allows for a total of four values
Wait, four?
If you come from traditional, strongly typed languages you might be familiar with the concept
of void: A type telling you that functions and methods return nothing when called.
symbol is a primitive data type in JavaScript and TypeScript, which, amongst other things,
can be used for object properties. Compared to number and string, symbols have some unique
features that make them stand out.
You might well see that my blog starts to center around TypeScript a lot recently. This might look like a strong deviation from what I usually blog and advocate: Performant, accessible and resilient web sites.
React typings for TypeScript come with lots of interfaces for all possible HTML elements out there. But sometimes, your browsers, your frameworks or your code are a little bit ahead of what’s possible.
Mapped types are great, as they allow for the flexibility in object structures JavaScript is known for. But they have some crucial implications on the type system. Take this example:
TypeScript is a structural type system. This means as long as your data structure satisfies a contract, TypeScript will allow it. Even if you have too many keys declared.
If you are doing traditional OOP with TypeScript, the structural features of TypeScript might sometimes get in your way. Look at the following class hierachy for instance:
Now that we have everything wired up, it’s time to record, direct and stream! If you missed the previous parts, check out the table of contents to quickyl jump to a previous section.
We successfully set up the projector in the first chapter. We are able to record the speaker’s video as described in the second chapter. Now let there be sound!