Vim: word vs WORD

Solution 1:

A WORD is always delimited by whitespace.
A word is delimited by non-keyword characters, which are configurable. Whitespace characters aren't keywords, and usually other characters (like ()[],-) aren't, neither. Therefore, a word usually is smaller than a WORD; the word-navigation is more fine-grained.

Example

This "stuff" is not-so difficult!
wwww  wwwww  ww www ww wwwwwwwww    " (key)words, delimiters are non-keywords: "-! and whitespace
WWWW WWWWWWW WW WWWWWW WWWWWWWWWW   " WORDS, delimiters are whitespace only

Solution 2:

To supplement the previous answers... I visualise it like this; WORD is bigger than word, it encompasses more... enter image description here

Solution 3:

If I do viw ("select inner word") while my cursor is on app in the following line, it selects app:

app/views/layouts/admin.blade.php

If I do viW (WORD) while my cursor is at the same place, it selects the whole sequence of characters. A WORD includes characters that words, which are like English words, do not, such as asterisks, slashes, parentheses, brackets, etc.

Solution 4:

According to Vim documentation ( :h 03.1 )

A word ends at a non-word character, such as a ".", "-" or ")".
A WORD ends strictly with a white-space. This may not be a word in normal sense, hence the uppercase.

eg.

           ge      b          w                             e
           <-     <-         --->                          --->
    This is-a line, with special/separated/words (and some more). ~
       <----- <-----         -------------------->         ----->
         gE      B                   W                       E

If your cursor is at m (of more above)

a word would mean 'more' (i.e delimited by ')' non-word character)
whereas a WORD would mean 'more).' (i.e. delimited by white-space only)

similarly, If your cursor is at p (of special)

a word would mean 'special'
whereas a WORD would mean 'special/separated/words'

Solution 5:

That's a grammar problem while understanding the definition of "word".

I get stuck at first in Chinese version of this definition (could be miss-translation).

The definition is definitely correct, but it should be read like that:

A word consists of:
   [(a sequence of letters,digits and underscores),
or (a sequence of other non-blank characters)], 
separated with white space (spaces, tabs, <EOL>).

Whitespace characters were only needed when delimiting two same types of 'word'

More examples in brackets as follow:

(example^&$%^Example) three "word" :(example), (^&$%^) and (Example)

(^&^&^^ &&^&^) two "word" : (^&^&^^) and (&&^&^)

(we're in stackoverflow) five "word" :(we), ('), (re), (in) and (stackoverflow)