..:: 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         914  0.5  0.5 1306528 85104 ?       Ssl  Aug04 294:38 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa         935  0.7  0.8 11786840 132480 ?     Ssl  Aug04 437:44 node /home/sasa/dex8/dex8-api/starter.js
sasa         938  0.4  0.4 1306588 75916 ?       Ssl  Aug04 246:45 node /home/sasa/regoch/regoch-www/server
sasa         945  0.3  0.4 1303752 71012 ?       Ssl  Aug04 213:00 node /home/sasa/dex8/dex8-panel/server/index.js
sasa         947  0.7  0.6 11820820 99396 ?      Ssl  Aug04 435:10 node /home/sasa/dex8/dex8-www/server/index.js
sasa         966  0.5  0.5 11807952 96192 ?      Ssl  Aug04 326:49 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa         980  0.7  0.5 1330216 84012 ?       Ssl  Aug04 443:28 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa         997  0.3  0.4 1303608 71984 ?       Ssl  Aug04 215:17 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1021  0.3  0.3 1297448 64888 ?       Ssl  Aug04 212:10 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1065  0.6  0.5 11801500 92636 ?      Ssl  Aug04 360:43 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa        1074  0.5  0.6 1150720 102824 ?      Ssl  Aug04 351:43 node /home/sasa/voovuu/voovuu-api/starter.js
sasa        1136  0.6  0.9 11850916 152216 ?     Ssl  Aug04 409:39 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1148  0.3  0.4 11794644 78320 ?      Ssl  Aug04 234:40 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa        1197  0.3  0.3 1099884 63376 ?       Ssl  Aug04 219:24 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1199  0.3  0.4 22279548 79208 ?      Ssl  Aug04 222:17 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1308  0.3  0.3 1099872 63824 ?       Ssl  Aug04 218:43 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1325  0.3  0.3 1099360 62796 ?       Ssl  Aug04 218:34 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1393  0.7  0.8 22327868 145492 ?     Ssl  Aug04 456:21 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1395  0.3  0.3 1099884 62952 ?       Ssl  Aug04 219:39 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1489  0.3  0.3 1100384 63880 ?       Ssl  Aug04 219:28 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1496  0.3  0.3 1100640 65384 ?       Ssl  Aug04 218:21 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1607  0.3  0.3 1099872 63332 ?       Ssl  Aug04 218:48 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1608  0.3  0.3 1099872 62956 ?       Ssl  Aug04 217:40 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1686  1.0  0.9 11849024 151084 ?     Ssl  Aug04 618:32 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
www-data  475112  0.0  0.0   2608   532 ?        S    12:49   0:00 sh -c ps -aux | grep node
www-data  475114  0.0  0.0   3304   644 ?        S    12:49   0:00 grep node
sasa     1371685  0.4  0.5 11797416 82904 ?      Ssl  Aug16 172:01 node /home/sasa/mikosoft-info/solar-wind-energy/server/index.js
sasa     1460918  0.4  0.3 1300136 64808 ?       Ssl  Aug17 169:30 node /home/sasa/sites-nodejs/oxygen-free-copper/server.js