Are you using trying out Typescript for the first time and getting the error “TS1153: let declarations are only available when targeting ECMAScript 6” when trying to declare variables with the “let” statement?
Well you need to update to a more recent Typescript version – thankfully its very easy (if you have npm installed) 🙂
1) Open command window and type “npm install -g typescript” (without the quotes). This installs latest stable version.
2) Take note of the install directory which is displayed in the command window
3) Open Intellij settings -> Languages & Frameworks -> Typescript -> compiler version
4) Change that to the lib folder of the typescript install directory.
That’s it 😀