..:: 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 1303236 80516 ?       Ssl  Oct24 269:54 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa        1200  0.9  0.8 11722864 138860 ?     Ssl  Oct24 473:21 node /home/sasa/dex8/dex8-api/starter.js
sasa        1207  0.4  0.4 1305932 74092 ?       Ssl  Oct24 221:54 node /home/sasa/regoch/regoch-www/server
sasa        1208  0.3  0.4 1304912 72956 ?       Ssl  Oct24 193:28 node /home/sasa/dex8/dex8-panel/server/index.js
sasa        1224  0.9  0.7 11851116 115204 ?     Ssl  Oct24 466:58 node /home/sasa/dex8/dex8-www/server/index.js
sasa        1236  0.5  0.6 11810828 98380 ?      Ssl  Oct24 296:08 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa        1255  0.7  0.5 1330860 84676 ?       Ssl  Oct24 396:22 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa        1257  0.3  0.4 1301028 68860 ?       Ssl  Oct24 196:36 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa        1289  0.3  0.4 1297724 67400 ?       Ssl  Oct24 193:52 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa        1363  3.2  2.7 12173684 452228 ?     Ssl  Oct24 1654:26 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1449  0.3  0.4 1168104 66016 ?       Ssl  Oct24 203:12 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1528  1.7  2.6 33095364 430112 ?     Ssl  Oct24 901:25 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1529  0.3  0.3 1100388 64432 ?       Ssl  Oct24 203:03 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1606  0.3  0.3 1100132 64224 ?       Ssl  Oct24 203:05 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1607  0.3  0.3 1100900 65108 ?       Ssl  Oct24 202:31 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1705  0.3  0.3 1101160 65132 ?       Ssl  Oct24 202:25 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1706  0.3  0.3 1100900 64508 ?       Ssl  Oct24 202:22 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1805  0.3  0.4 1167200 66000 ?       Ssl  Oct24 202:34 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1807  0.3  0.3 1100384 63952 ?       Ssl  Oct24 198:28 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1885  0.3  0.3 1100136 63452 ?       Ssl  Oct24 199:49 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1886  1.6  1.0 11876012 164080 ?     Ssl  Oct24 860:28 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa     2628167  0.8  0.7 1170068 125844 ?      Ssl  Nov04 298:23 node /home/sasa/voovuu/voovuu-api/starter.js
sasa     3168557  0.6  0.5 11801292 90336 ?      Ssl  Nov06 211:33 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa     3169051  0.4  0.5 11798408 83536 ?      Ssl  Nov06 138:09 node /home/sasa/@mikosoft/dodo-examples/server/index.js
www-data 3672536  0.0  0.0   2608   596 ?        S    10:45   0:00 sh -c ps -aux | grep node
www-data 3672538  0.0  0.0   3304   724 ?        S    10:45   0:00 grep node