Satya, The "event loop" doesn't matter until two things happen: 1. You actually perform asynchronous work. (A for loop doesn't count. Please read http://nodemanual.org/latest/nodejs_dev_guide/writing_asynchronous_code.html ) 2. You understand *and deeply care about* the boundaries between the code that will be run on each "tick" of said event loop. (For now, assume you neither care nor understand. Then read http://nodemanual.org/latest/nodejs_dev_guide/writing_asynchronous_code.htmlagain, and identify those boundaries. [SPOILER: The only non-first-tick code is on lines 5-8.])
Until then, Keep Calm and Carry On. -Schoon On Sat, Sep 29, 2012 at 2:01 AM, Satya Prakash Prasad < [email protected]> wrote: > I understand that Node.js has the concept of event-driven, asynchronous > callbacks, by utilizing an event loop. > > database.query("SELECT * FROM hugetable", function(rows) { var result = > rows; }); > console.log("Hello World"); > > Here, instead of expecting *database.query()* to directly return a result > to us, we pass it a second parameter, an anonymous function. > Now, Node.js can handle the database request asynchronously. Provided that > *database.query()* is part of an asynchronous library, this is what > Node.js does: just as before, it takes the query and sends it to the > database. But instead of waiting for it to be finished, it makes a mental > note that says "When at some point in the future the database server is > done and sends the result of the query, then I have to execute the > anonymous function that was passed to *database.query()*." > > I am trying the same with a sample code (as I am a newbie and not reached > till Node.js DB interactions): > > [root@example]# cat server8.js > function myfun(noparm , afterend) > { > for ( var i =0; i < 10; i ++) > console.log("The valus is " + i); > } > > function mynextfn() > { > console.log("Hello World"); > } > function afterend() > { > console.log("Hello afterend"); > } > > myfun(0, afterend); > mynextfn(); > [root@idc-bldtool01 example]# node server8.js > The valus is 0 > The valus is 1 > The valus is 2 > The valus is 3 > The valus is 4 > The valus is 5 > The valus is 6 > The valus is 7 > The valus is 8 > The valus is 9 > Hello World > [root@iexample]# > > As such I do not see the " concept of event-driven, asynchronous > callbacks, by utilizing an event loop" ? > > Can anyone please help me in implementing some basic examples? > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
