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 soak up such a perform, plus a quantity worth, after which execute that perform with the worth.
Observe 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. For example, the frameworks tsdx, Angular, and Nest all know find out how to mechanically flip a TypeScript codebase into its matching JavaScript code with little intervention in your half.
When you’re working with a construct device like Babel or webpack (amongst others), these instruments also can deal with TypeScript tasks, so long as you put in TypeScript dealing with as an extension or allow it manually. For example, with webpack, you’d set up the ts-loader bundle by means of npm, after which arrange a webpack.config.js file to incorporate your .ts recordsdata.
The important thing to transferring an current 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 every little thing directly, and you may take the time to experiment with determining the very best varieties to make use of throughout your challenge’s codebase.
