Encountering a syntax error when attempting to utilize the colon symbol for specifying data types

Currently, I am a novice who is delving into the world of TypeScript. Here is a snippet of code that I have written:

let num: number = 123;
console.log(123);

However, when attempting to run this file using Node.js and saving it as test.ts, I encounter the error message 

SyntaxError: Unexpected token ':'
.

From my understanding, this is the correct way to specify the type of a variable in TypeScript, right? Just to provide some context, I am utilizing VSCode for my coding environment. Additionally, I have both Node.js and npm properly installed, along with TypeScript. I double-checked their versions as well. Despite scouring the internet, I could not find a solution to this seemingly trivial problem.

Could someone kindly point out what mistake I might be making?

typescript

Answer №1

NodeJS does not natively support TypeScript. TypeScript must be transpiled into JavaScript before it can run. While there are modules and engines that can compile TypeScript on-the-fly, such as Deno, ultimately the code is still being translated into JavaScript during runtime.

Note: TypeScript offers type inference, allowing developers to omit explicit type declarations without sacrificing type safety. For example, you can remove ":number" from a variable declaration and TypeScript will still correctly infer that the variable is of type number.

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