How to compare file using Command Prompt and Visual Studio 2015

How to compare file using Command Prompt and Visual Studio 2015
1. open command prompt
2. go to visual studio path : "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE"
3. example :

.\devenv.exe /diff “C:\b.txt” “C:\a.txt” “SOURCE” “TARGET”