Find and replace whole words in vim

Question

To find and replace all instances of a word in vim, I use

%s/word/newword/g 

How can I change this so that it finds only instances of the “word,” which are whole words?

Answer 1

You can use \< to match the beginning of a word and \> to match the end:

 %s/\<word\>/newword/g 

Answer 2

For case-sensitive substitution .. you can use "\ C"

 :%s/\<word\>\C/newword/g 

It replaces only the "word" with a new word, leaving others like Word, WORD ... unreplaced.

Answer 3

For search and replace with PCRE support, you can use the perldo or rubydo as described here: http://vim.wikia.com/wiki/Perl_compatible_regular_expressions

For example:

 :perldo s/\bword\b/newword/g