RegEx for Javascript to allow only alphanumeric

Question

I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just w

Answer 1

Use the word character class. The following is equivalent to a ^[a-zA-Z0-9_]+$:

^\w+$

Explanation:

• ^ start of string
• \w any word character (A-Z, a-z, 0-9, _).
• $ end of string

Use /[^\w]|_/g if you don't want to match the underscore.