regex - Regex for url make flexible begining

Question

How to modify the following regex pattern to make it without requiring http or https:

<input type="url" 
 pattern="^(ht|f)tp(s?)\:\/\/[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\:\'\/\\\+=&amp;%\$#_]*)$"
 validationMessage="Enter a valid web url />

User just type into normal www. is ok, not require http:// or https://.

I tried following, and typed into www.google.com, but not working.

pattern="^[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\:\'\/\\\+=&%\$#_]*)$"

Answer 1

pattern="^(?:(ht|f)tp(s?)\:\/\/|\/\/)?[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\:\'\/\\\+=&%\$#_]*)$"

这将让你做例如：

http://www.mysite.com
//www.mysite.com
www.mysite.com

Answer 2

你可以试试这个：

^((ht|f)tp(s?)\:\/\/)?[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\:\'\/\\\+=&%\$#_]*)$

这将允许输入如下：

http://www.google.com
www.google.com
https://www.google.com
google.com

并且不会允许以下内容：

//www.google.com

希望这就是你要找的。