angular upgrade guide code example

Example 1: angular 8 to 9

First, update to the latest version of 8
ng update @angular/cli@8 @angular/core@8

Then, update to 9
ng update @angular/cli @angular/core

Example 2: update angular

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

Example 3: update angular materia;

npm update @angular/material @angular/cdk