how to run .js with node code example

Example 1: run node js

node name_app.js

Example 2: how to run a js file in node

Save your .js file in the same folder as node.js,
For windows , Usually location is- "C:\Program Files\nodejs"
Open 'Command prompt and locate node.js folder' OR directly open 'Node.js command prompt' and type 
>> node (file_name).js