Ignoring a character along with word boundary in regex

Question

I am using gsub in Ruby to make a word within text bold. I am using a word boundary so as to not make letters within other words bold, but am finding that this ignores word

Answer 1

The #{word} syntax doesn't work for regular expressions. Use Regexp.new instead:

word = "below"
text = "I said, 'look out below'"

reg = Regexp.new("\\b#{word}\\b", true)
text = text.gsub(reg, "\\0")

Note that when using sting you need to escape \b to \\b, or it is interpreted as a backspace. If word may contain special regex characters, escape it using Regexp.escape.

Also, by replacing the string to #{word} you may change casing of the string: "BeloW" will be replaced to "below". \0 corrects this by replacing with the found word. In addition, I added \\b at the beginning, you don't want to look for "day" and end up with "sunday".