需要一个正则表达式来匹配字母后跟数字或大写字母

Question

I need a regular expression that can replace the lowercase letter n with a newline, but only when it is followed by a digit 0-9 or a capital letter.

For example, the string:
Company Buildingn100 Prospect Way

Should convert into:
Company Building
100 Prospect Way

I'm trying to sanitize this data in PHP, so the resulting expression needs to be compatible.

Answer 1

Try this:

n(?=[\dA-Z])

In PHP ( working example ):

$str = preg_replace("/n(?=[\dA-Z])/", "\n", $str);

(?=...) is a positive lookahead - it checks what's after the n we matched, but doesn't match it, so the next character isn't replaced.

Answer 2

$result = preg_replace("/n(?=[\dA-Z])/", "\n", $subject);

will do this if by capital letter you mean ASCII letters.

$result = preg_replace("/n(?=[\d\p{Lu}])/u", "\n", $subject);

if you're using Unicode.