built in function to combine overlapping string sequences in php?

Question

Is there a built in function in PHP that would combine 2 strings into 1?

Example:

$string1 = 'abcde';
$string2 = 'cdefg';

Combine to get: abcdefg.

If the exact overlapping sequence and the position are known, then it is possible to write a code to merge them.

TIA

Answer 1

No, there is no builtin function, but you can easily write one yourself by using substr and a loop to see how much of the strings that overlap.

Answer 2

It's possible using substr_replace() and strcspn():

$string1 = 'abcde';
$string2 = 'cdefgh';

echo substr_replace($string1, $string2, strcspn($string1, $string2)); // abcdefgh