Difference between npm start node app js when starting app

Question

I have installed an application using the command express new  filename    I have just learned that you can start an application using   npm start   Thus far I have used   node app js   to start my server  Anyone know what the difference is between the two  Thanks

User · Accepted Answer

From the man page  npm start      runs a package s  start  script  if one was provided    If no version is specified  then it starts the  active  version    Admittedly  that description is completely unhelpful  and that s all it says  At least it s more documented than socket io   Anyhow  what really happens is that npm looks in your package json file  and if you have something like      scripts      start    coffee server coffee      then it will do that  If npm can t find your start script  it defaults to      node server js    nbsp

User · Answer

The documentation has been updated  My answer has substantial changes vs the accepted answer  I wanted to reflect documentation is up-to-date  and accepted answer has a few broken links   Also  I didn t understand when the accepted answer said  it defaults to node server js   I think the documentation clarifies the default behavior      npm-start      Start a package      Synopsis      npm start  --  lt args gt        Description      This runs an arbitrary command specified in the package s  start    property of its  scripts  object  If no  start  property is specified   on the  scripts  object  it will run node server js    In summary  running npm start could do one of two things    npm start  command name   Run an arbitrary command  i e  if such command is specified  in the start property of package json s scripts object  npm start  Else if no start property exists  or no command name is passed   Run node server js   which may not be appropriate  for example the OP doesn t have server js  the OP runs nodeapp js   I said I would list only 2 items  but are other possibilities  i e  error cases   For example  if there is no package json in the directory where you run npm start  you may see an error  npm ERR  enoent ENOENT  no such file or directory  open     package json

[node.js] Difference between `npm start` & `node app.js`, when starting app?

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