Global Angular CLI version greater than local version

To answer one of the questions, it is necessary to have both a global and local install for the tools to work.

If you try to run ng serve on an application without the local install of the CLI (global install only), you will get the following error.

You have to be inside an Angular CLI project in order to use the serve command.

It will also print this message:

Please take the following steps to avoid issues:
"npm install --save-dev @angular/cli@latest"

Run that npm command to update the CLI locally, and avoid the warning that you are getting.

Other question: It looks like they do not have to be in sync, but it's probably best that they are in order to avoid any unusual behavior with the tool, or any inconsistencies with the code the tool generates.

Why do we need both the global install, and a local install?

The global install is needed to start a new application. The ng new <app-name> command is run using the global installation of the CLI. In fact, if you try to run ng new while inside the folder structure of an existing CLI application, you get this lovely error:

You cannot use the new command inside an Angular CLI project.

Other commands that can be run from the global install are ng help, ng get/set with the --global option, ng version, ng doc, and ng completion.

The local install of the CLI is used after an application has been built. This way, when new versions of the CLI are available, you can update your global install, and not affect the local install. This is good for the stability of a project. Most ng commands only make sense with the local version, like lint, build and serve, etc.

According to the CLI GitHub readme, to update the CLI you must update the global and local package. However, I have used the CLI where the global and local version vary without any trouble so far. If I ever run across an error related to having the global and local CLI versions out of sync, I will post that here.

This works for me: it will update local version to latest

npm uninstall --save-dev angular-cli
npm install --save-dev @angular/cli@latest
npm install

to verify version

  ng --version

This is how I solved the issue.

Copy and run these commands

ng --version
npm install --save-dev @angular/cli@latest
ng --version

npm uninstall -g @angular/cli
npm cache verify
npm install -g @angular/cli@latest

Then in your Local project package:

rm -rf node_modules dist 
npm install --save-dev @angular/cli@latest
npm i 
ng update @angular/cli 
ng update @angular/core
npm install --save-dev @angular-devkit/build-angular

Was getting below error Error: Unexpected end of JSON input Unexpected end of JSON input Above steps helped from this post Can't update angular to version 6