Capitalize first letter of each word in a selection using vim

Question

In vim, I know we can use ~ to capitalize a single char (as mentioned in this question), but is there a way to capitalize the first letter of each word in a sel

Answer 1

:help case says:

To turn one line into title caps, make every first letter of a word
uppercase: >
    : s/\v<(.)(\w*)/\u\1\L\2/g

Explanation:

:                      # Enter ex command line mode.

space                  # The space after the colon means that there is no
                       # address range i.e. line,line or % for entire
                       # file.

s/pattern/result/g     # The overall search and replace command uses
                       # forward slashes.  The g means to apply the
                       # change to every thing on the line. If there
                       # g is missing, then change just the first match
                       # is changed.

The pattern portion has this meaning.

\v                     # Means to enter very magic mode.
<                      # Find the beginning of a word boundary.
(.)                    # The first () construct is a capture group. 
                       # Inside the () a single ., dot, means match any
                       #  character.
(\w*)                  # The second () capture group contains \w*. This
                       # means find one or more word caracters. \w* is
                       # shorthand for [a-zA-Z0-9_].

The result or replacement portion has this meaning:

\u                     # Means to uppercase the following character.
\1                     # Each () capture group is assigned a number
                       # from 1 to 9. \1 or back slash one says use what
                       # I captured in the first capture group.
\L                     # Means to lowercase all the following characters.
\2                     # Use the second capture group

Result:

ROPER STATE PARK
Roper State Park  

An alternate to the very magic mode:

    : % s/\<\(.\)\(\w*\)/\u\1\L\2/g
    # Each capture group requires a backslash to enable their meta
    # character meaning i.e. "\(\)" verses "()".