..:: 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         831  0.5  0.5 1305208 82400 ?       Ssl  Jun15 163:55 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa         843  0.5  0.6 11699012 105020 ?     Ssl  Jun15 165:15 node /home/sasa/dex8/dex8-api/starter.js
sasa         858  0.3  0.4 1304640 72780 ?       Ssl  Jun15 125:33 node /home/sasa/regoch/regoch-www/server
sasa         867  0.3  0.4 1302604 67008 ?       Ssl  Jun15 117:24 node /home/sasa/dex8/dex8-panel/server/index.js
sasa         886  0.7  0.6 11819084 105812 ?     Ssl  Jun15 244:23 node /home/sasa/dex8/dex8-www/server/index.js
sasa         888  0.5  0.5 11796264 82112 ?      Ssl  Jun15 173:47 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa         904  0.7  0.4 1329652 81112 ?       Ssl  Jun15 231:22 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa         910  0.3  0.4 1300240 69188 ?       Ssl  Jun15 118:15 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa         969  0.3  0.4 1297976 65972 ?       Ssl  Jun15 116:57 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa         970  0.6  0.5 11822328 98036 ?      Ssl  Jun15 213:45 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa        1010  0.6  0.6 1148612 104708 ?      Ssl  Jun15 197:54 node /home/sasa/voovuu/voovuu-api/starter.js
sasa        1016  0.8  1.1 11874348 186816 ?     Ssl  Jun15 256:20 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1086  0.4  0.4 11794656 77920 ?      Ssl  Jun15 127:11 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa        1089  0.3  0.3 1099356 64780 ?       Ssl  Jun15 119:50 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1159  0.3  0.4 22280508 80200 ?      Ssl  Jun15 122:38 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1160  0.3  0.3 1099356 64268 ?       Ssl  Jun15 119:57 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1241  0.3  0.3 1101208 63664 ?       Ssl  Jun15 120:20 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1242  0.4  0.5 22285032 85392 ?      Ssl  Jun15 127:16 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1323  0.3  0.3 1099356 64600 ?       Ssl  Jun15 120:04 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1324  0.3  0.3 1099616 64172 ?       Ssl  Jun15 120:00 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1398  0.3  0.3 1099104 63640 ?       Ssl  Jun15 120:01 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1400  0.3  0.3 1099612 64504 ?       Ssl  Jun15 120:24 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1465  0.3  0.3 1099616 64140 ?       Ssl  Jun15 119:59 node /home/sasa/dex8/dex8-worker/starter.js
sasa      178968  0.8  0.6 11812292 99420 ?      Ssl  Jun17 234:53 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa      337381  1.2  1.4 1470236 241588 ?      Ssl  Jun19 315:34 node /home/sasa/crypto/dex-arbitrage-bot/scripts/observer/index2
www-data 1604870  0.0  0.0   2608   592 ?        S    01:33   0:00 sh -c ps -aux | grep node
www-data 1604872  0.0  0.0   3304   728 ?        S    01:33   0:00 grep node