Typescript Deep Dive by Basarat Ali Syed
Typescript Deep Dive by Basarat Ali Syed
Typescript Deep Dive by Basarat Ali Syed
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TypeScript <strong>Deep</strong> <strong>Dive</strong><br />
Variables<br />
For example to tell TypeScript about the process variable you can do:<br />
declare var process:any;<br />
You don't need to do this for process as there is already a community maintained node.ts<br />
This allows you to use the process variable without TypeScript complaining:<br />
process.exit()<br />
We recommend using an interface wherever possible e.g:<br />
interface Process {<br />
exit(code?:number):void;<br />
}<br />
declare var process: Process;<br />
This allows other people to extend the nature of these global variables while still telling TypeScript about such<br />
modifications. E.g. consider the following case where we add an exitWithLogging function to process for our amusement:<br />
interface Process {<br />
exitWithLogging(code?:number):void;<br />
}<br />
process.exitWithLogging = function() {<br />
console.log("exiting");<br />
process.exit.apply(process,arguments);<br />
}<br />
Lets look at interfaces in a bit more detail next.<br />
Variables<br />
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