Positive & Negative Lookaheads - RegEx Beginner Tutorial

Lookahead assertions in regular expressions come in two types - positive lookaheads and negative lookaheads. They're used similarly in C#, JavaScript, Java, or Python. These are just two examples of regex assertions, and this beginner tutorial shows you how to use the positive lookahead and how to use the negative lookahead. You can always test your regular expression patterns on a free online regex tester like regex101.com (not sponsored) to check if your lookahead's not working. ☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁ Subscribe to the channel ✔️ https://www.youtube.com/channel/UCQzgvO9ALGmBZr75m8OiAiA Become a member to access exclusive perks. https://www.youtube.com/channel/UCQzgvO9ALGmBZr75m8OiAiA/join CUSTOM SASUKE THEME for Visual Studio, exclusive content, and more on Patreon. https://www.patreon.com/heightabovesealevel Click the 🔔 to turn on notifications so you don't miss anything. Come hang out on DISCORD! Discord: https://discord.gg/kbBbZrArpK Other awesome videos worth checking out: Quantifiers in Regular Expressions https://youtu.be/vSypjqFr8oU How to Match Numbers Using Regular Expressions https://youtu.be/rGO7RNf2x0Y Regular Expressions for Beginners Playlist https://www.youtube.com/playlist?list=PLKCFltnebRSVlQLKfIAJTmRAhU75CpeBt A tip is always appreciated :) https://streamelements.com/avatarvick/tip ☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁ Timestamps: 00:00 - What are Lookaheads in Regular Expressions? 01:02 - Positive Lookahead (?=) 02:33 - Negative Lookahead (?!) 03:20 - Positive Lookahead Visual Studio Demo 04:10 - Claim Your Custom Visual Studio Theme 04:33 - Negative Lookahead Visual Studio Demo 05:10 - Quick Recap 05:34 - What's Next? ☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁ Here's my other social media - amazing stuff over there too! 🎮 TWITCH ➼ https://www.twitch.tv/avatarvick 📷 INSTAGRAM ➼ https://www.instagram.com/heightabovesealevel 😂 TWITTER ➼ https://www.twitter.com/Vicktor_Oti (VICKTA) ☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁ 🎵 Music provided by: StreamBeats by Harris Heller https://www.streambeats.com/ Certain gifs courtesy of tenor.com ☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁☁ #programming #regularexpressions #regex Thank you for watching. Subscribe, and I'll see you in the next video.