..:: Source code - 01callback.js ::..

/**
 * basic usage of callbacks
 */

/* MAIN FUNCTION */
function addnum(x, cb) {
  console.log('x=' + x);
  cb(x);
}


/* CALLBACKS */

//callback which adds 5
function cb5(a) {
  var rez = a + 5;
  console.log('a+5=' + rez);
}

//callback which adds 100
function cb100(a) {
  var rez = a + 100;
  console.log('a+100=' + rez);
}

//execute main function with callback cb5
addnum(2, cb5);

console.log();

//execute main function with callback cb100
addnum(2, cb100);


/* $node 01callback
x=2
a+5=7

x=2
a+100=102
 */

..:: NodeJS Console - 01callback.js ::..

x=2
a+5=7

x=2
a+100=102

$ps -aux | grep node (list all node processes)
sasa        1194  0.4  0.4 1302468 78724 ?       Ssl  Oct24  32:46 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa        1200  0.7  0.8 11718640 134176 ?     Ssl  Oct24  57:27 node /home/sasa/dex8/dex8-api/starter.js
sasa        1207  0.3  0.4 1301220 68420 ?       Ssl  Oct24  24:42 node /home/sasa/regoch/regoch-www/server
sasa        1208  0.3  0.4 1299336 65748 ?       Ssl  Oct24  23:26 node /home/sasa/dex8/dex8-panel/server/index.js
sasa        1224  0.7  0.5 11821092 95352 ?      Ssl  Oct24  55:12 node /home/sasa/dex8/dex8-www/server/index.js
sasa        1236  0.4  0.5 11811596 95924 ?      Ssl  Oct24  30:16 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa        1255  0.5  0.4 1328700 80836 ?       Ssl  Oct24  44:26 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa        1257  0.3  0.4 1301128 68608 ?       Ssl  Oct24  24:03 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1289  0.3  0.3 1296500 63236 ?       Ssl  Oct24  23:22 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1292  0.4  0.5 11820012 92224 ?      Ssl  Oct24  32:05 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa        1361  0.6  0.6 1154308 109348 ?      Ssl  Oct24  49:24 node /home/sasa/voovuu/voovuu-api/starter.js
sasa        1363  1.9  2.0 12102392 336012 ?     Ssl  Oct24 145:28 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1441  0.3  0.4 11793416 76292 ?      Ssl  Oct24  25:18 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa        1449  0.3  0.3 1165032 63212 ?       Ssl  Oct24  24:27 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1528  1.3  0.8 22320940 139016 ?     Ssl  Oct24 103:51 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1529  0.3  0.3 1099364 63420 ?       Ssl  Oct24  24:24 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1606  0.3  0.3 1098340 62456 ?       Ssl  Oct24  24:36 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1607  0.3  0.3 1099364 63856 ?       Ssl  Oct24  24:26 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1705  0.3  0.3 1099624 64704 ?       Ssl  Oct24  24:25 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1706  0.3  0.3 1099108 63660 ?       Ssl  Oct24  24:24 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1805  0.3  0.3 1099616 63440 ?       Ssl  Oct24  24:25 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1807  0.3  0.3 1099872 63864 ?       Ssl  Oct24  24:07 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1885  0.3  0.3 1099112 63760 ?       Ssl  Oct24  24:10 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1886  0.7  0.6 11815684 113660 ?     Ssl  Oct24  56:04 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
www-data 1151785  0.0  0.0   2608   536 ?        S    19:13   0:00 sh -c ps -aux | grep node
www-data 1151787  0.0  0.0   3304   648 ?        S    19:13   0:00 grep node