How can I format a float to a certain number of decimal and integer digits?

ruby

Solution

You can use `sprintf('%05.2f', value)`.

The key is that the format is `width . precision`, where `width` indicates a minimum width for the entire number, not just the integer portion.

def print_float(value)
  sprintf('%05.2f', value)
end
print_float(1)
# => "01.00" 
print_float(2.4)
# => "02.40" 
print_float(1.4455)
# => "01.45"

Problem

I am trying to format a float in Ruby to exactly four digits, including the decimal. For instance: ``` 1 => 01.00 2.4 => 02.40 1.4455 => 01.45 ``` Right now, I am trying to format the float as follows: ``` str_result = " %.2f " %result ``` Which successfully limits the decimal places to two. I'm also aware of: ``` str_result = " %2d " %result ``` Which succesfully turns `1` into `01`, but loses the decimal places. I tried to combine these like so: ``` str_result = " %2.2f " %result ``` to no apparent effect. It has the same results as `%.2f`. Is there a way to force Ruby to format the string into this four digit format?

Original source