When I multiply 3 * 1.1 in JavaScript instead of returning 3.3, it results in 3.30000000000000003, Why is this?
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2[relevante](http://www.smbc-comics.com/index.php?db=comics&id=2999#comic) – nicosantangelo Nov 10 '14 at 12:55
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4Welcome to Stack Overflow! Currently, we only support English, so would you be so kind to translate your question? – This company is turning evil. Nov 10 '14 at 12:55
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1This is because js stores numbers as floating point values and floating points arithmetics aren't always 100 % accurate. 0.2 + 0.1 for example does not give 0.3 in javascript but 0.30000000000000004 – Markai Nov 10 '14 at 12:56
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http://stackoverflow.com/questions/1458633/elegant-workaround-for-javascript-floating-point-number-problem – Dimag Kharab Nov 10 '14 at 12:57
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http://floating-point-gui.de/ – Dimag Kharab Nov 10 '14 at 12:58
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Do you have any more constructive question than "Why is this?" – Anders Marzi Tornblad Nov 10 '14 at 12:58
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That's because numbers in computers are represented as floating point numbers, which have limited precision. Some operations will cause tiny errors and there's nothing you can do about that.
It's also a reason to never compare numbers using ==.
Filburt
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So if we should not compare it by `==` , then what is the recommended way? – Ayush Kumar Jun 14 '21 at 05:46
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@AyushKumar compare them to some tolerance: `a == b` becomes `Math.abs(a - b) < TOLERANCE`. What that tolerance is depends on context. Note that JS has the concept of "safe integers", which IIRC are up to [2^53](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER), so if you're only doing additions, subtractions, multiplications, or divisions of even integers, by integers, that result in values in that range, you can be sure they're the same and you can use `==`. – This company is turning evil. Jun 14 '21 at 14:16