Today I am going to talk about new features in Typescript 4.0.
TypeScript 4.0 comes with lots of new features to make JavaScript development easier.
You can label tuple elements.
You can write:
type Range = [start: number, end: number];
to restrict args
to have a string and a number.
you can also write:
type Foo = [first: number, second?: string, ...rest: any[]];
to have rest entries in your tuple.
If your tuple has type Foo
, then the tuple starts with a number and a string.
Then the rest of the entries can be anything.
Labels don’t require you to name your variables differently when destructuring.
For example, if you have:
function foo(x: [first: string, second: number]) {
const [a, b] = x;
}
then you can name the destructured variables anything you want.
#software-development #typescript-with-react #typescript #typescript-4 #react native