How to round to 2 decimal 2.2034 and have 2.20 and not 2.2 in Ruby

Question

Actually I do not know how this is called and that is why I ask here.

I am working with currency and this way of presentation is important.

In ruby I need to have a value like 2.20 and not 2.2.

Examples:

2.201.round(2) -> 2.20 and not 2.2

3.80989.round(2) -> 3.80 and not 3.8

The problem is with the final 0, when it is another number there is no problem. 2.345.round(2) -> 2.35

Any idea?

are you really working with currency and store data in float??? — Anatoly, Sep 09 '15 at 11:58

score 4 · Accepted Answer · edited May 23 '17 at 10:26

4

Something like this using formatting

x = 2.2
puts "%.2f" %x # => 2.20

When dealing with money and currencies, you shouldn't trust floating point numbers. Why? Check this.

There is a special gem for dealing with money.

edited May 23 '17 at 10:26

Community

answered Sep 09 '15 at 11:59

mic-kul

1

Note that the linked question has rounding issues despite using the Money gem. – Stefan Sep 09 '15 at 13:11

Marek Lipka · Answer 2 · 2015-09-09T12:48:27.370

3

You can use sprintf method:

sprintf('%.2f', 2.201)
# => '2.20'

edited Sep 09 '15 at 12:48

answered Sep 09 '15 at 11:58

Marek Lipka

2 Answers2