The capitalize and capitalize! method

Question

Hi everyone!

I just have a question about the usage of .capitalize method. Being more precise, about it's usage in an input, just like:

print "What's your name?"
name=gets.chop.capitalize

I have tested in this way and just works perfectly, but then I knew about the .capitalize!

print "What's your name?"
name=gets.chop.capitalize!

And I just realized that if I write in the input the words already capitalized, they simply don't return the word, the field appears blank.

I get it that .capitalize! change the variable so then I'll not need to every time capitalize it when I need to print or something like that. But I don't get this kind of "bug". I don't know even if it's a bug, but really make me stop e think and I would really apreciate some help.

Thank you already.

Answer 1

Indeed "capitalize!" returns nil (a.k.a null) if no changes were made.

Check if the word is already capitalized or .capitalize if is different than nil.

Answer 2

In Ruby, convention tell that a function with exclamation dot ( ! ) append to it, is the version which modify the argument while the not appended version modify a copy and return it... So:

text='this is a sample text'
print text.capialize # output: This is a sample text
print text # output: this is a sample text
text.capitalize!
print text # output: This is a sample text