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JavaScript floating point -- 0.1 + 0.2 !== 0.3
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floating point0.1 + 0.2precisionIEEE 754centsmoney
browsernodejs
Error Messages
unexpected decimal resultProblem
Arithmetic with decimal numbers produces unexpected results. Equality comparisons with decimal results are unreliable. Causes bugs in financial calculations.
Solution
Never compare floats with ===. For money: work in cents (integers). For display: toFixed(2). For precise math: decimal.js.
Why
IEEE 754 cannot represent 0.1 exactly in binary. Representation errors accumulate.
Code Snippets
Float comparison and money handling
// Problem
0.1 + 0.2 === 0.3 // false!
// Fix: work in cents
const price = 1050; // $10.50
const display = (price / 100).toFixed(2); // "10.50"Revisions (0)
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