ng port 4200 is already in use code example
Example 1: Port 4200 is already in use. Use '--port' to specify a different port
sudo lsof -t -i tcp:4200 | xargs kill -9
Example 2: cancel ng server port
Using your terminal, find the PID of port 4200
netstat -ano | findstr :4200
Kill task by the PID Number (Replace 15940)
taskkill /PID 15940 /F