ruby - How do I round to two decimal places? -

i want items rounded such this:

(5.101 * 100).round / 100.0 

to output this:

5.10 

instead of this:

5.1 

how do in ruby?

there couple ways, favor using string's % (format) operator:

'%.2f' % [(5.101 * 100).round / 100.0] # => "5.10" 

kernel's sprintf method has documentation various flags , modifiers. there's kernel's printf but, said, i'd go %.