..:: 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         831  0.5  0.4 1304176 80348 ?       Ssl  Jun15 121:31 node /home/sasa/.pm2/modules/pm2-logrotate/node_modules/pm2-logr
sasa         843  0.5  0.6 11699640 104484 ?     Ssl  Jun15 116:59 node /home/sasa/dex8/dex8-api/starter.js
sasa         858  0.4  0.4 1303596 72144 ?       Ssl  Jun15  91:46 node /home/sasa/regoch/regoch-www/server
sasa         867  0.3  0.4 1298972 66416 ?       Ssl  Jun15  86:38 node /home/sasa/dex8/dex8-panel/server/index.js
sasa         886  0.8  0.7 11831652 117556 ?     Ssl  Jun15 183:00 node /home/sasa/dex8/dex8-www/server/index.js
sasa         888  0.5  0.4 11794160 79992 ?      Ssl  Jun15 126:52 node /home/sasa/mikosoft_hr/www-mikosoft-hr/server/index.js
sasa         904  0.7  0.4 1329652 81620 ?       Ssl  Jun15 168:26 node /home/sasa/mikosoft-info/api-mikosoft-info/starter.js
sasa         910  0.3  0.4 1300780 69896 ?       Ssl  Jun15  87:23 node /home/sasa/mikosoft-info/www-mikosoft-info/server/index.js
sasa         969  0.3  0.3 1297484 64544 ?       Ssl  Jun15  86:24 node /home/sasa/dex8/dex8-kiosk/server/index.js
sasa         970  0.6  0.5 11811796 95032 ?      Ssl  Jun15 155:19 node /home/sasa/mikosoft-info/dodo-mikosoft-info/server/index.js
sasa        1010  0.6  0.6 1147316 103452 ?      Ssl  Jun15 145:50 node /home/sasa/voovuu/voovuu-api/starter.js
sasa        1016  0.8  1.1 11873484 186240 ?     Ssl  Jun15 193:03 node /home/sasa/voovuu/voovuu-pub/server/index.js
sasa        1086  0.4  0.4 11794400 77456 ?      Ssl  Jun15  93:34 node /home/sasa/@mikosoft/dodo-examples/server/index.js
sasa        1089  0.3  0.4 1099356 66016 ?       Ssl  Jun15  88:32 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1159  0.3  0.4 22276156 76044 ?      Ssl  Jun15  89:59 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1160  0.3  0.3 1099612 64216 ?       Ssl  Jun15  88:38 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1241  0.3  0.3 1101464 63192 ?       Ssl  Jun15  88:55 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1242  0.4  0.5 22284380 84740 ?      Ssl  Jun15  94:11 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1323  0.3  0.3 1099356 63828 ?       Ssl  Jun15  88:46 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1324  0.3  0.3 1099872 64584 ?       Ssl  Jun15  88:32 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1398  0.3  0.3 1099616 64436 ?       Ssl  Jun15  88:43 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1400  0.3  0.3 1099612 63952 ?       Ssl  Jun15  88:59 node /home/sasa/dex8/dex8-worker/starter.js
sasa        1465  0.3  0.3 1099872 64580 ?       Ssl  Jun15  88:45 node /home/sasa/dex8/dex8-worker/starter.js
sasa      178968  0.8  0.6 11810912 98756 ?      Ssl  Jun17 161:34 node /home/sasa/mikosoft-info/crypto-mikosoft-info/server/index.
sasa      337381  1.2  0.5 1317564 91672 ?       Ssl  Jun19 203:01 node /home/sasa/crypto/dex-arbitrage-bot/scripts/observer/index2
www-data 1163750  0.0  0.0   2608   532 ?        S    00:06   0:00 sh -c ps -aux | grep node
www-data 1163752  0.0  0.0   3304   656 ?        S    00:06   0:00 grep node