lookbehind means the analysis of the preceding characters before the regular expression is matched. Lexicurio rates it Rare gem — a strength score of 84 out of 100.
noun
- The analysis of the preceding characters before the regular expression is matched.“[There] are times when it's useful to be able to look to the left of the current position being considered to see what the past had to say about a particular pattern. That is the purpose of lookbehinds.”