Here's an example of a regex to validate us phone numbers https://regexper.com/#%2F%5E(1%5Cs%3F)%3F(%5B0-9%5D%7B3%7D%7C%5C(%5B0-9%5D%7B3%7D%5C))%5B%5Cs%7C-%5D%

Here's an example of a regex to validate us phone numbers https://regexper.com/#%2F%5E(1%5Cs%3F)%3F(%5B0-9%5D%7B3%7D%7C%5C(%5B0-9%5D%7B3%7D%5C))%5B%5Cs%7C-%5D%3F%5B0-9%5D%7B3%7D%5B%5Cs%7C-%5D%3F%5B0-9%5D%7B4%7D%24%2Fgm https://regexper.com/#%2F%5E(1%5Cs%3F)%3F(%5B0-9%5D%7B3%7D%7... From https://www.freecodecamp.org/challenges/validate-us-telephone-numbers https://www.freecodecamp.org/challenges/validate-us-telephon... I found these 11 videos most helpful when learning regex from codecourse https://www.youtube.com/watch?v=GVZOJ1rEnUg&index=1&list=PLfdtiltiRHWGRPyPMGuLPWuiWgEI9Kp1w https://www.youtube.com/watch?v=GVZOJ1rEnUg&index=1&list=PLf...