Округление и форматирование чисел в React: адаптивный подход

Всем привет, на связи снова я — Дмитрий, React-разработчик. И сегодня хочу поднять тему, которая на первый взгляд кажется простой, но на практике может доставить немало сюрпризов - округление и форматирование чисел в интерфейсе. Изначально может показаться, что здесь сложного практически ничего нет: есть toFixed() и toLocaleString(), но практика показывает, что реальные интерфейсы почти никогда в это не укладываются. Почему? Потому что в разных диапазонах чисел пользователи ждут разного поведения. Именно с этим сталкиваются разработчики при работе с таблицами, отчётами, финансовыми данными и аналитикой. В этой статье я предложу функцию, которая решает определенные задачи округления и форматирования, и разберу, как она подбирает количество знаков после запятой в зависимости от величины числа Ниже опишу требования к форматированию, которые легли в основу функции, и покажу, как они отражаются в коде и в интерфейсе.

https://habr.com/ru/companies/gnivc/articles/985170/

#javascript #react #mathematics #frontend #rounding #formatting #numbers #math #working_with_numbers #case

Nested rounding question.
First, recall rounding
If the first non-significant digit is less than 5, then the least significant digit remains unchanged. 4.44 -> 4.4
If the first non-significant digit is greater than 5, the least significant digit is incremented by 1. 4.46 -> 4.5
And usually, the last applies to first non-significant digit equal to 5. 4.45 -> 4.5

The issue is with nested/double rounding.
Say a number 4.451 and assume is rounded first to 2 significant digits, so 4.45. Assume a second rounding step where this number is rounded to 1 significant digit, so 4.5. It is correctly rounded, since abs(4.5 - 4.451) < abs(4.4 - 4.451)

However, let's repeat the process with another number, 4.449. After 1st rounding step it become 4.45, after second, 4.5. However on one step it must be rounded to 4.4.

So my question is if there is some notation for the 4.5 marking if it is a rounded from a greater or lower number, for example 4.45^{-} and 4.45^{+} or with the signs in any other left/right x super/sub-index position?

And may we deal with such situation with R?

**Remark**: I don't claim R rounds as described. I ask if it's possible to print rounded numbers with R so it marks those ended such as 4.5 so readers of the printed results know if such number is = or is rounded from a > / < number.

#Rstats #rounding

Rounding (2022) Available July 29

#horror – #horrormovies – #Rounding – #MusicBoxSelects – After a traumatic incident, a driven young medical resident transfers to a rural hospital for a fresh start, but the demons of his past start to catch up to him when he becomes consumed by the case of a patient with mysterious symptoms. Director Alex Thompson assembles […]

#horror #ad #Releases #Rounding

https://horrornerdonline.com/2025/06/rounding-2022-available-july-29/

‘Rounding’ Review: Modest Thriller Conjures Atmospheric but Convoluted Suspense in a Rural Hospital
#Variety #Reviews #AlexThompson #Rounding

https://variety.com/2025/film/reviews/rounding-review-1236304637/

Friday, February 14, 2025: Rounding Premieres Today on Digital

#horror – #horrormovies – #Rounding – A driven young medical resident transfers to a rural hospital for a fresh start. There, the demons of his past start to catch up to him when he becomes consumed by the case of a young asthma patient. …

#horror #ad #Premieres #Rounding

https://horrornerdonline.com/2025/02/friday-february-14-2025-rounding-premieres-today-on-digital/

Rounding | Official Trailer | Available on February 14

#horror – #Trailers – #horrormovies – #Rounding – After a traumatic incident, a driven young medical resident transfers to a rural hospital for a fresh start, but the demons of his past start to catch up to him when he becomes consumed by the case of a patient with mysterious symptoms. …

#ad #horror #Rounding #Trailers

https://horrornerdonline.com/2025/01/rounding-official-trailer-available-on-february-14/

‘Rounding’ Trailer: Sidney Flanigan Might Be Possessed in Alex Thompson’s Psychological Thriller
#IndieWire #News #Trailers #Alexthompson #Film #ROUNDING

https://www.indiewire.com/news/trailers/rounding-trailer-alex-thompson-1235083342/