What is the javascript antecedent assertion

This article mainly introduces the relevant knowledge of "what is the javascript antecedent assertion". The editor shows you the operation process through the actual case. The operation method is simple, fast and practical. I hope this "what is the javascript antecedent assertion" article can help you solve the problem.

Description

1. The first assertion is the match pattern that tells JavaScript to search forward in the string. It may be useful if you want to search for multiple matching patterns on the same string.

2. there are two kinds of antecedent assertions: positive antecedent assertion and negative antecedent assertion.

Example

Let quit = "qu"; let noquit = "qt"; let quRegex= / Q (? = u) /; let qRegex = / Q (?! U) /; quit.match (quRegex); noquit.match (qRegex); this is the end of the introduction of "what is the javascript antecedent assertion". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.