..:: 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  0.5  0.5 1304972 84288 ?       Ssl  Oct24 434:45 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa        1200  1.0  0.8 11724800 141816 ?     Ssl  Oct24 780:10 node /home/sasa/dex8/dex8-api/starter.js
sasa        1208  0.4  0.4 1305000 73340 ?       Ssl  Oct24 313:21 node /home/sasa/dex8/dex8-panel/server/index.js
sasa        1224  1.0  0.7 11833576 115252 ?     Ssl  Oct24 747:23 node /home/sasa/dex8/dex8-www/server/index.js
sasa        1236  0.6  0.6 11811852 100568 ?     Ssl  Oct24 492:49 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa        1255  0.9  0.5 1330860 83776 ?       Ssl  Oct24 664:22 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa        1257  0.4  0.4 1301160 69560 ?       Ssl  Oct24 318:39 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1289  0.4  0.4 1297580 66388 ?       Ssl  Oct24 313:19 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1363  3.5  2.7 12143328 446008 ?     Ssl  Oct24 2604:27 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1449  0.4  0.3 1232360 65424 ?       Ssl  Oct24 329:21 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1528  2.0  2.7 33107276 445124 ?     Ssl  Oct24 1466:28 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1529  0.4  0.3 1100644 64736 ?       Ssl  Oct24 328:30 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1606  0.4  0.3 1100900 65032 ?       Ssl  Oct24 329:42 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1607  0.4  0.3 1101156 64812 ?       Ssl  Oct24 328:38 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1705  0.4  0.4 1101928 66340 ?       Ssl  Oct24 328:20 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1706  0.4  0.3 1101412 65324 ?       Ssl  Oct24 327:46 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1805  0.4  0.4 1168224 66840 ?       Ssl  Oct24 328:45 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1807  0.4  0.3 1100384 63724 ?       Ssl  Oct24 321:05 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1885  0.4  0.3 1099880 63872 ?       Ssl  Oct24 322:40 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1886  2.3  1.0 11861676 164332 ?     Ssl  Oct24 1740:41 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa     2628167  1.0  0.8 1174332 131064 ?      Ssl  Nov04 575:44 node /home/sasa/voovuu/voovuu-api/starter.js
sasa     3168557  0.7  0.5 11823608 97960 ?      Ssl  Nov06 427:58 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa     3169051  0.5  0.5 11800712 83168 ?      Ssl  Nov06 287:56 node /home/sasa/@mikosoft/dodo-examples/server/index.js
www-data 3226610  0.0  0.0   2608   596 ?        S    05:54   0:00 sh -c node 02callback_settimeout2.js
www-data 3226611  1.2  0.2 726148 39232 ?        Sl   05:54   0:00 node 02callback_settimeout2.js
www-data 3226629  0.0  0.0   2608   528 ?        S    05:54   0:00 sh -c ps -aux | grep node
www-data 3226631  0.0  0.0   3304   652 ?        S    05:54   0:00 grep node