The Ruby Way: Solutions and Techniques in Ruby Programming, Second Edition

2.30. Removing Duplicate Characters

Runs of duplicate characters may be removed using the squeeze method:

s1 = "bookkeeper"
s2 = s1.squeeze         # "bokeper"
s3 = "Hello..."
s4 = s3.squeeze         # "Helo."
If a parameter is specified, only those characters will be squeezed.
s5 = s3.squeeze(".")    # "Hello."

This parameter follows the same rules as the one for the count method (see the section 2.28, “Counting Characters in Strings” earlier in this chapter); that is, it understands the hyphen and the caret.

There is also a squeeze! method.