Question

I need to find first white space position of a string.

Something like: str_pos($content, ' ') but I must do this with regular expression because str_pos don’t detect every time white spaces in my content.

Answer 1

You can use the regex:

^(\S*)\s

which matches the non-whitespace characters before the first whitespace. Then you can find the length of the non-whitespace characters which will be the index of the first white-space.

if(preg_match('/^(\S*)\s/',$input,$m)) {
   echo "Position of first white-space is ",strlen($m[1]);
} else {
   echo "Now whitespace in $input";
}