..:: Source code - 020number_float_rounding_error.js ::..

/**
 * Binary floating point
 */
var x, y, z, num;

x = 0.3 - 0.2;
y = 0.2 - 0.1;
z = 0.5 - 0.4;

console.log(x); //0.09999999999999998
console.log(y); //0.1
console.log(z); //0.09999999999999998

// correction with parseFloat and toPrecision
console.log(parseFloat(z.toPrecision(12))); //0.1
 

..:: NodeJS Console - 020number_float_rounding_error.js ::..

$ node 020number_float_rounding_error.js
0.09999999999999998
0.1
0.09999999999999998
0.1
$ps -aux | grep node (list all node processes)
sasa        1194  0.5  0.5 1305684 83956 ?       Ssl   2025 936:42 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa        1208  0.3  0.4 1304744 71860 ?       Ssl   2025 670:36 node /home/sasa/dex8/dex8-panel/server/index.js
sasa        1224  0.8  0.7 11854140 119012 ?     Ssl   2025 1487:43 node /home/sasa/dex8/dex8-www/server/index.js
sasa        1236  0.5  0.6 11818352 105388 ?     Ssl   2025 1060:45 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa        1257  0.3  0.4 1306968 72580 ?       Ssl   2025 681:10 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1289  0.3  0.4 1298092 68632 ?       Ssl   2025 669:26 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1363  4.5  3.1 12223384 523512 ?     Ssl   2025 8228:50 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1886  3.1  1.6 11955288 265872 ?     Ssl   2025 5627:54 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa     1214480  0.4  0.7 22311424 125956 ?     Ssl   2025 368:35 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214483  0.3  0.3 1100800 64336 ?       Ssl   2025 301:59 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214536  0.3  0.3 1100804 65052 ?       Ssl   2025 301:10 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214544  0.3  0.3 1100776 65108 ?       Ssl   2025 303:23 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214588  0.3  0.3 1100548 64804 ?       Ssl   2025 301:52 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214617  0.3  0.4 1100928 65940 ?       Ssl   2025 301:10 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214641  0.3  0.3 1100392 64096 ?       Ssl   2025 296:46 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1214671  0.3  0.3 1099360 63376 ?       Ssl   2025 295:42 node /home/sasa/dex8/dex8-worker/starter.js
sasa     1215731  0.7  0.7 11708296 123020 ?     Ssl   2025 674:35 node /home/sasa/dex8/dex8-api/starter.js
sasa     1216489  0.3  0.3 1100792 64484 ?       Ssl   2025 300:37 node /home/sasa/dex8/dex8-worker/starter.js
sasa     2509059  0.6  0.6 11832312 111560 ?     Ssl  Feb14 113:46 node /home/sasa/miko/miko-hr/server/index.js
sasa     2628167  0.8  0.8 1176664 131780 ?      Ssl   2025 1479:10 node /home/sasa/voovuu/voovuu-api/starter.js
sasa     3168557  0.6  0.6 11817388 100708 ?     Ssl   2025 1051:33 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa     3169051  0.5  0.5 11798920 84336 ?      Ssl   2025 845:01 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa     3264954  0.6  0.5 1330464 83596 ?       Ssl  Feb21  49:50 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa     3832236  0.3  0.4 1102684 67072 ?       Ssl  03:03   1:54 node /home/sasa/dex8/dex8-worker/starter.js
www-data 3875132  0.0  0.0   2608   596 ?        S    12:24   0:00 sh -c ps -aux | grep node
www-data 3875134  0.0  0.0   3304   724 ?        S    12:24   0:00 grep node