perform runFn(fn: (arg: quantity) => any, worth: quantity): any {
return fn(worth);
}
runFn would settle for a perform that takes a single quantity as an argument and returns any worth. runFn would absorb such a perform, plus a quantity worth, after which execute that perform with the worth.
Notice that right here we use the arrow notation to point what the handed perform returns, not a colon as we do the principle perform signature.
Constructing a TypeScript challenge
Many construct instruments within the JavaScript ecosystem are actually TypeScript-aware. As an example, the frameworks tsdx, Angular, and Nest all know easy methods to mechanically flip a TypeScript codebase into its matching JavaScript code with little intervention in your half.
Should you’re working with a construct instrument like Babel or webpack (amongst others), these instruments may also deal with TypeScript initiatives, so long as you put in TypeScript dealing with as an extension or allow it manually. As an example, with webpack, you’d set up the ts-loader bundle by way of npm, after which arrange a webpack.config.js file to incorporate your .ts recordsdata.
The important thing to shifting an present JavaScript challenge to TypeScript is to method it a step at a time—migrate one module at a time, then one perform at a time. As a result of TypeScript can coexist with common JavaScript, you aren’t obliged emigrate the whole lot without delay, and you’ll take the time to experiment with determining one of the best sorts to make use of throughout your challenge’s codebase.