..:: 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  0.4 1302808 80788 ?       Ssl  Oct24 224:24 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa        1200  0.9  0.8 11722320 139112 ?     Ssl  Oct24 393:27 node /home/sasa/dex8/dex8-api/starter.js
sasa        1207  0.4  0.4 1305712 73660 ?       Ssl  Oct24 180:07 node /home/sasa/regoch/regoch-www/server
sasa        1208  0.3  0.4 1304656 72080 ?       Ssl  Oct24 160:14 node /home/sasa/dex8/dex8-panel/server/index.js
sasa        1224  0.9  0.5 11801636 93896 ?      Ssl  Oct24 392:16 node /home/sasa/dex8/dex8-www/server/index.js
sasa        1236  0.5  0.6 11813644 98728 ?      Ssl  Oct24 244:16 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa        1255  0.7  0.5 1330064 83088 ?       Ssl  Oct24 319:42 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa        1257  0.3  0.4 1301160 69684 ?       Ssl  Oct24 162:43 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1289  0.3  0.4 1297336 66580 ?       Ssl  Oct24 160:38 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1363  3.2  2.9 12196404 475396 ?     Ssl  Oct24 1343:03 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1449  0.4  0.3 1166312 64456 ?       Ssl  Oct24 168:21 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1528  1.8  2.6 22631984 428892 ?     Ssl  Oct24 749:28 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1529  0.4  0.3 1100132 63880 ?       Ssl  Oct24 168:17 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1606  0.4  0.3 1100132 64180 ?       Ssl  Oct24 168:20 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1607  0.4  0.3 1100644 64932 ?       Ssl  Oct24 167:49 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1705  0.4  0.3 1100904 64992 ?       Ssl  Oct24 167:33 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1706  0.4  0.3 1100900 64464 ?       Ssl  Oct24 167:47 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1805  0.4  0.3 1100384 65060 ?       Ssl  Oct24 167:47 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1807  0.3  0.3 1100384 64348 ?       Ssl  Oct24 164:22 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1885  0.4  0.3 1099880 63884 ?       Ssl  Oct24 165:24 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1886  1.5  0.9 11853812 155488 ?     Ssl  Oct24 633:26 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
www-data 2143804  0.0  0.0   2608   592 ?        S    07:15   0:00 sh -c ps -aux | grep node
www-data 2143806  0.0  0.0   3304   720 ?        R    07:15   0:00 grep node
sasa     2628167  0.8  0.7 1165128 121232 ?      Ssl  Nov04 222:37 node /home/sasa/voovuu/voovuu-api/starter.js
sasa     3168557  0.6  0.5 11820728 96608 ?      Ssl  Nov06 149:40 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa     3169051  0.4  0.5 11798408 83496 ?      Ssl  Nov06  99:22 node /home/sasa/@mikosoft/dodo-examples/server/index.js