..:: 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  0.4 1303396 78328 ?       Ssl  Jun15 173:23 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa         843  0.5  0.6 11699532 104892 ?     Ssl  Jun15 177:27 node /home/sasa/dex8/dex8-api/starter.js
sasa         858  0.3  0.4 1304640 73112 ?       Ssl  Jun15 133:12 node /home/sasa/regoch/regoch-www/server
sasa         867  0.3  0.4 1300556 68240 ?       Ssl  Jun15 124:21 node /home/sasa/dex8/dex8-panel/server/index.js
sasa         886  0.7  0.5 11798864 88448 ?      Ssl  Jun15 264:00 node /home/sasa/dex8/dex8-www/server/index.js
sasa         888  0.5  0.4 11794048 79656 ?      Ssl  Jun15 184:13 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa         904  0.7  0.5 1329652 82084 ?       Ssl  Jun15 245:53 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa         910  0.3  0.4 1300240 69192 ?       Ssl  Jun15 125:13 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa         969  0.3  0.3 1297976 65068 ?       Ssl  Jun15 123:53 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa         970  0.6  0.5 11813624 95940 ?      Ssl  Jun15 225:57 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa        1010  0.6  0.6 1148612 104472 ?      Ssl  Jun15 209:51 node /home/sasa/voovuu/voovuu-api/starter.js
sasa        1016  0.8  1.1 11908084 194596 ?     Ssl  Jun15 271:04 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1086  0.4  0.4 11794656 78308 ?      Ssl  Jun15 134:53 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa        1089  0.3  0.4 1100380 65620 ?       Ssl  Jun15 126:53 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1159  0.3  0.4 22276156 75888 ?      Ssl  Jun15 130:00 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1160  0.3  0.3 1100380 65236 ?       Ssl  Jun15 127:04 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1241  0.3  0.3 1102488 64304 ?       Ssl  Jun15 127:27 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1242  0.4  0.5 22284008 84088 ?      Ssl  Jun15 134:49 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1323  0.3  0.3 1100124 64760 ?       Ssl  Jun15 127:07 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1324  0.3  0.3 1100896 64872 ?       Ssl  Jun15 127:04 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1398  0.3  0.3 1100384 65036 ?       Ssl  Jun15 127:07 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1400  0.3  0.3 1100636 64560 ?       Ssl  Jun15 127:30 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1465  0.3  0.3 1100896 65144 ?       Ssl  Jun15 127:00 node /home/sasa/dex8/dex8-worker/starter.js
sasa      178968  0.8  0.6 11811988 99504 ?      Ssl  Jun17 251:52 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa      337381  1.2  1.4 1469776 240948 ?      Ssl  Jun19 339:12 node /home/sasa/crypto/dex-arbitrage-bot/scripts/observer/index2
www-data 1704701  0.0  0.0   2608   592 ?        S    10:17   0:00 sh -c ps -aux | grep node
www-data 1704703  0.0  0.0   3304   732 ?        S    10:17   0:00 grep node