Regex to match the first letter in a word ONLY

Question

This SHOULD be simple for some reason I seem to be stretching the boundaries of my regex knowledge. I simply need a regex that will match the first letter in a word. I only want letters from an array that start with x y or z . This seems to reduce the amount of items in the array... but I'm not sure why since the results aren't what I'm expecting.

Regex regex = new Regex(@"\b[x|y|z]");
string[] array = text.Where(x => regex.IsMatch(x)).ToArray()); // 'text' is an array 

Answer 1

Try

\b([xyz]\w*)

\\w* means zero to many word characters. When using [] the | is implied between the characters. So, [xyz] means x, y, or z. Then placing the () captures the word. So, in short we find something that is the start of a word then capture a string of word characters starting with x, y, or z.

Also, you can change \\w with [A-Za-z] since some will include _ and numbers as a word character:)

Can also go here to test regex. Even though it is for php , python , and javascript it still is nice to test:)

Hope this helps some!

Answer 2

这可能是你在搜索的内容：

Regex regex = new Regex(@"^(x|y|z).+$");

Answer 3

我试过这个，它似乎做你需要的：

new Regex(@"\b[x|y|z](?=\w*\b)")

Answer 4

If i understood your answer right, then you want to match words that start with any of the letters x , y or z . The answer you accepted would match everything after the occurence of x or y or z .

try this instead:

[xyz]\w+

in a text like

lalalalla nananna x xaa yaaa zaaa lalala

it would match the three words

xaa 
yaaa 
zaaa

individually.

if you also want to match single occurences of the letters, use

[xyz]\w*

instead, which would match

x
xaa 
yaaa 
zaaa

.