"SyntaxError: Unexpected token?" appears when displaying the "tsc" command.

Question

I am new to typescript, I tried converting a typescript file to a javascript file by running the command tsc filename.ts. But it shows error.

C:Program Files (x86)Nodistbinnode_modulestypescriptlibtsc.js:93
  for (let i = startIndex ?? 0; i < array.length; i ) {
                           ^

SyntaxError: Unexpected token?
    at Module._compile (internal/modules/cjs/loader.js:749:23)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:816:10)
    at Module.load (internal/modules/cjs/loader.js:672:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:612:12)
    at Function.Module._load (internal/modules/cjs/loader.js:604:3)
    at Module.require (internal/modules/cjs/loader.js:711:19)
    at require (internal/modules/cjs/helpers.js:14:16)
    at Object.<anonymous> (C:Program Files (x86)Nodistbinnode_modulestypescriptbintsc:2:1)
    at Module._compile (internal/modules/cjs/loader.js:805:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:816:10)

I tried installing node to the latest version.

Answer 1

I encountered the same problem using TypeScript 5.1.6 and Node 12.x versions.

You get this problem because of this combination. I downgraded my TypeScript to 4.9.5 and it works fine for me.

Please check the pictures below for reference:

https://www.typescriptlang.org /docs/handbook/release-notes/typescript-5-1.html