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Use numeric separators for large numeric literals

Friday, February 21, 2020

Numeric separators provide improved readability of large numeric literals by creating a visual separation between the digit groups. The numeric separators proposal for ECMAScript is currently a stage 3 proposal, has been implemented in TypeScript 2.7, and is already available in Chrome, Firefox and Safari. Check out caniuse.com for the latest support of numeric separators in modern browsers.

Instructions

Do

use numeric separators to provide visual separation in order to improve code readability

Avoid

large numeric literals without visual separators

Code Examples

use numeric separators

const BIG = 1_000_000_000   // ohh, it _is_ a billion!

const APR = 26_99 // phew, only 26.99%

large numeric literals without separators

const BIG = 1000000000   // it's a billion. no, ten million. maybe, 10 billion. ugh

const APR = 2699 // is that 26.99 percent or 2,699% ?!?
Brian Love

I am a software engineer and Google Developer Expert in Web Technologies and Angular with a passion for learning, writing, speaking, teaching and mentoring. I regularly speaks at conferences and meetups around the country, and co-authored "Why Angular for the Enterprise" for O'Reilly. When not coding, I enjoy skiing, hiking, and being in the outdoors. I started lookout.dev to break down the barriers of learning in public. Learning in public fosters growth - for ourselves and others.

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