In Python, I can do substring operations based on a regex like this.
rsDate = re.search(r"[0-9]{2}/[0-9]{2}/[0-9]{4}", testString)
filteredDate = rsDate.group()
filteredDate = re.sub(r"([0-9]{2})/([0-9]{2})/([0-9]{4})", r"\3\2\1", filteredDate)
What's the PHP equivalent to this?