Precision Errors In Javascript

Recently I have posted a poll 🎙📟 in linkedin

𝘞𝘩𝘢𝘵 𝘸𝘪𝘭𝘭 𝘣𝘦 𝘵𝘩𝘦 𝘷𝘢𝘭𝘶𝘦 𝘰𝘧 𝘹 𝘪𝘯 𝘵𝘩𝘦 𝘣𝘦𝘭𝘰𝘸 𝘑𝘢𝘷𝘢𝘚𝘤𝘳𝘪𝘱𝘵 𝘤𝘰𝘥𝘦👨‍💻

𝘭𝘦𝘵 𝘹=0.1 + 0.2 === 0.3;

Even though mathematically this is true, In JavaScript x will be evaluated as false. Majority(66/120) of the people voted for wrong answer. This may be confusing for most of the people and good thing to be aware of! Here is why!📢

👉JavaScript (like many other programming languages) uses binary floating-point arithmetic (IEEE 754 standard), which can cause precision errors when representing certain decimal numbers. For example: 0.1 + 0.2 𝘳𝘦𝘴𝘶𝘭𝘵𝘴 𝘪𝘯 0.30000000000000004, 𝘯𝘰𝘵 𝘦𝘹𝘢𝘤𝘵𝘭𝘺 0.3.

👉You can handle this in below ways: 1️⃣𝘌𝘱𝘴𝘪𝘭𝘰𝘯 𝘊𝘰𝘮𝘱𝘢𝘳𝘪𝘴𝘰𝘯:Compare floating-point numbers in JavaScript, you can use a small threshold value called epsilon:

𝘔𝘢𝘵𝘩.𝘢𝘣𝘴(0.1+ 0.2- 0.3) < 𝘕𝘶𝘮𝘣𝘦𝘳.𝘌𝘗𝘚𝘐𝘓𝘖𝘕// 𝘵𝘳𝘶𝘦

▪This checks if the difference between the two numbers is within a very small range, effectively treating them as equal.

Read more about epsilon here

2️⃣𝘋𝘦𝘤𝘪𝘮𝘢𝘭 𝘓𝘪𝘣𝘳𝘢𝘳𝘪𝘦𝘴: Use libraries like BigDecimal.js or Big.js for exact decimal arithmetic when high precision is needed.

Here you can find more details on Number encoding

Poll In Linkedin	Output From Console

This Content was originally posted in linkedin View Post