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Andrew Stelmach
12,583 PointsExtra Credit: multiply two numbers and display the answer as a number with two decimal places
How do you get Ruby to change a Fixnum, or a Float, (or even a String?) into a number with two decimal places.
I'm thinking of converting the number into currency, but this feels like cheating.
3 Answers
Maciej Czuchnowski
36,441 PointsOne way of doing this is by using the round method like this:
number.round(2)
The problem is, if you have a number like 1.999876, it will return 2.0, so it's not always what you expect.
The other way I know looks like it was taken from C programming language:
sprintf('%.2f', number)
Assuming it's a float, if it's anything else, you have to change the f to something else. Non-floats (also strings) can be changed into a float like this:
number.to_f
Andrew Stelmach
12,583 PointsThanks! That helped a lot. It worked. My code:
puts "Enter your first number:"
number1 = gets.to_f
puts "Enter the second number (to be multiplied by your first):"
number2 = gets.to_f
answer = sprintf('%.2f', number1*number2)
puts "These two numbers multiplied together = #{answer}"
Jeffery Briggette
Courses Plus Student 5,567 PointsThe to_f method won't make any difference, since the sprintf function will add the 2 decimal places regardless whether or not the number variables are a float or a fixnum. You can just as easily have the .to_i method. The outcome will be the same. Just a little tid-bit.
Maciej Czuchnowski
36,441 PointsOK, try and run Andrew's code with to_f's changed to to_i and try it for numbers 2.99 and 1. The result will be 2.00, which is not what we want, so to_f is actually required here :). We use sprintf to only SHOW 2 decimal places in case the user enters more or the result would have more than two.
Jeffery Briggette
Courses Plus Student 5,567 PointsOK. I see what you are saying. Didn't think of someone multiplying floats. So .to_f will pretty much cover all our bases. I get it. Thank you for your input.