如何在不丢失角色的情况下preg_split？

Question

I have a string like this

$string = "Hello; how are you;Hey, I am fine";
$new = preg_split("/;\w/", $string);
print_r($new);

I am trying to split the string only when there is no white-space between the words and ";". But when I do this, I lose the H from Hey. It's probably because the split happens through the recognition of ;H. Could someone tell me how to prevent this?

My output:

$array  =   [
  0 => [
    0 => 'Hello; how are you ',
    1 => 0,
  ],
  1 => [
    0 => 'ey, I am fine',
    1 => 21,
  ],
]

Answer 1

You might use a word boundary \b:

\b;\b

$string = "Hello; how are you;Hey, I am fine";
$new = preg_split("/\b;\b/", $string);
print_r($new);

Demo

Or a negative lookahead and negative lookbehind

(?<! );(?! )

Demo