How to detect whether a string is in URL format using javascript?

Question

I think the question title seems to explain eveything. I want to detect whether a string is in URL format or not using javascript.

Any help appreciated.

Answer 1

function IsURL(url) {

    var strRegex = "^((https|http|ftp|rtsp|mms)?://)"
        + "?(([0-9a-z_!~*'().&=+$%-]+: )?[0-9a-z_!~*'().&=+$%-]+@)?" //ftp的user@
        + "(([0-9]{1,3}\.){3}[0-9]{1,3}" // IP形式的URL- 199.194.52.184
        + "|" // 允许IP和DOMAIN（域名）
        + "([0-9a-z_!~*'()-]+\.)*" // 域名- www.
        + "([0-9a-z][0-9a-z-]{0,61})?[0-9a-z]\." // 二级域名
        + "[a-z]{2,6})" // first level domain- .com or .museum
        + "(:[0-9]{1,4})?" // 端口- :80
        + "((/?)|" // a slash isn't required if there is no file name
        + "(/[0-9a-z_!~*'().;?:@&=+$,%#-]+)+/?)$";
     var re=new RegExp(strRegex);
     return re.test(url);
 }

Debuggex Demo (Improved version which matches also 'localhost')