Ruby：计算浮点数中的数字

Question

Is there any worthy Ruby method to count the number of digits in a float? Also, how do I specify the precise when to_s float numbers?

Answer 1

# Number of digits

12345.23.to_s.split("").size -1 #=> 7

# The precious part

("." + 12345.23.to_s.split(".")[1]).to_f #=> .023

# I would rather used 
# 12345.23 - 12345.23.to_i 
# but this gives 0.22999999999563

Answer 2

to specify precision of a float in Ruby. you can use the round method.

number.round(2)

2 is the precision.

53.819.round(2) -> 53.82

Answer 3

我想你应该查看number_with_precision帮助器。

number_with_precision(13, :precision => 5) # => 13.00000