Regular expression to find occurrence of uppercase followed by lowercase

Question

Hi, I'm fairly new to Regex. Hoping someone would help me find a regular expression for finding occurrences of uppercase followed by lowercase. For example:

ABcDe

Here I would be hoping to find the 'B' and the 'D'

Thanks!

Answer 1

[A-Z][a-z]

(assuming English characters only)

Answer 2

You can use forward lookaheads. You haven't said which "flavour" of regex you're using, so here's a C# example:

var regex = new Regex(@"[A-Z](?=[a-z])");
string str = "ABcDef";
regex.Replace(str, "?");
Console.WriteLine(str); // outputs "A?c?ef"

Additionally, for international characters, you can use Unicode character classes:

var regex = new Regex(@"\p{Lu}(?=\p{Ll})");

Answer 3

I believe this is what you are looking for.

([A-Z])[a-z]

Answer 4

In Python:

import re

regex = re.compile("(?:([A-Z])[a-z])")

strdata = 'ABcDefGHIjk'

print [m.group(1) for m in regex.findinter(strdata) if m.group(1) ]