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fadhly-permata / flutter_money_formatter

"FlutterMoneyFormatter" is a Flutter extension to formatting various types of currencies according to the characteristics you like, without having to be tied to any localization.
https://pub.dartlang.org/packages/flutter_money_formatter
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Rounding Value #7

Closed LaksamanaGuntur closed 5 years ago

LaksamanaGuntur commented 5 years ago

Describe the bug I get a problem with rounding value

To Reproduce your sample : FlutterMoneyFormatter fmf = FlutterMoneyFormatter( amount: 12345678.9012345 ); and output with print(fo.compactNonSymbol); is 12.30M

My sample : i change amount with 12355678.9012345 (change number four to five) and output with print(fo.compactNonSymbol); is 12.40M

Expected behavior My Expectation is 12.35

Screenshots

Screen Shot 2019-07-29 at 12 26 56

Smartphone (please complete the following information):

Thanks!

fadhly-permata commented 5 years ago

English Version: Hi @LaksamanaGuntur, actually this is not part of flutter_money_formatter, the rounding results are obtained from the intl dependency.

However, as far as I know, rounding will usually use the round-up / round-down method by referring to the number on the right. So if we pay attention, the reason number 12355678.9012345 becomes 12.40M is, we will only take the first 4 digits (in your case that is, 1235), and the fourth number is 5, so the rounding method that will be used is definitely using the round-up method, and the result of rounding up from 1235 is 1240.

Remember, in the basic concept of rounding, the numbers 1,2,3,4 have definitely experienced round-down, and the numbers 5,6,7,8,9 have definitely been rounded up.

as an example:

525 = 500 717 = 700 1,250 = 1,300 2,781 = 2,800 4,524 = 4,500 5,359 = 5,400 6,168 = 6,000 + 100 + 68 = 6,000 + 100 + 100 = 6,200 6,998 = 6,000 + 900 + 98 = 6,000 + 900 + 100 = 7,000 10,343 = 10,000 + 300 + 43 = 10,000 + 300 + 0 = 10,300 7,423 = 7,400

Maybe if possible, in the next version I will add round-up and round-down features (by ignoring the basic concept of rounding numbers).

N.B: Please review the concept of rounding, and as an additional reference from me, (since you are Indonesian) this is a good article that discusses rounding numbers.

Versi Indonesia Hi @LaksamanaGuntur , sebetulnya hal ini bukan merupakan bagian dari flutter_money_formatter, hasil pembulatan tersebut didapat dari dependency intl.

Namun, sepanjang yang saya tau, pembulatan biasanya akan menggunakan metode pembulatan ke angka terdekat (round-up/round-down) dengan mengacu pada angka disebelah kanan. Jadi bila kita perhatikan, alasan angka 12355678.9012345 menjadi 12.40M adalah, kita hanya akan mengambil 4 digit pertama (pada kasus Anda yakni, 1235), dan angka ke-empat adalah 5, sehingga metode pembulatan yang akan digunakan sudah pasti menggunakan metode round-up (pembulatan ke-atas) dan hasil pembulatan ke atas dari 1235 adalah 1240.

Ingat, pada konsep dasar pembulatan, angka 1,2,3,4 sudah pasti mengalami pembulatan round-down, dan angka 5,6,7,8,9 sudah pasti mengalami pembulatan ke-atas.

sebagai contoh:

525 =  500
717 = 700
1.250 = 1.300
2.781 = 2.800
4.524 = 4.500
5.359 = 5.400
6.168 = 6.000 + 100 + 68 = 6.000 + 100 + 100 = 6.200
6.998 = 6.000 + 900 + 98 = 6.000 + 900 + 100 = 7.000
10.343 = 10.000 + 300 + 43 = 10.000 + 300 + 0 = 10.300
7.423 = 7.400

Mungkin bila memungkinkan, pada versi berikutnya akan saya tambahkan fitur round-up dan round-down (dengan mengabaikan konsep dasar pembulatan angka).

N.B: Silahkan pelajari kembali konsep pembulatan, dan sebagai referensi tambahan dari saya, (berhubung Anda orang Indonesia) maka ini artikel bagus yang membahas mengenai pembulatan angka