Split at capital letters in PHP?

Question

I found this similar question, but it doesn't answer my question, Split word by capital letter.

I have a string which is camel case. I want to break up that string at each capital letter like below.

$str = 'CamelCase'; // array('Camel', 'Case');

I have got this far:

$parts = preg_split('/(?=[A-Z])/', 'CamelCase');

But the resulting array always ends up with an empty value at the beginning! $parts looks like this

$parts = array('', 'Camel', 'Case');

How can I get rid of the empty value at the beginning of the array?

Answer 1

You can use the PREG_SPLIT_NO_EMPTY flag like this:

$parts = preg_split('/(?=[A-Z])/', 'CamelCase', -1, PREG_SPLIT_NO_EMPTY);

See the documentation for preg_split.

Answer 2

You need a positive-lookbehind. Try this:

$parts = preg_split('/(?<=\\w)(?=[A-Z])/', 'CamelCase')

array(2) {
  [0]=>
  string(5) "Camel"
  [1]=>
  string(4) "Case"
}