How to validate url?

Question

I want to validate urls. It should accept:

http://google.com

http://www.google.com

www.google.com

google.com

I refer Regex to match URL

Answer 1

function isUrl(s) {
    var regexp = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/
    return regexp.test(s);
}

Answer 2

This is a better way I think should be used to validate urls

reg = /https?:\/\/w{0,3}\w*?\.(\w*?\.)?\w{2,3}\S*|www\.(\w*?\.)?\w*?\.\w{2,3}\S*|(\w*?\.)?\w*?\.\w{2,3}[\/\?]\S*/
reg.test('www.google.com')    # will return true
reg.test('www.google')        # will return false

Let me know if you still not getting it correct.

Answer 3

This simple helper method uses Regex to validate URLs and will pass on each of your test cases. It also takes into account for whitespace so google.com/a white space/ will fail.

    public static bool ValidateUrl(string value, bool required, int minLength, int maxLength)
    {
        value = value.Trim();
        if (required == false && value == "") return true;
        if (required && value == "") return false;

        Regex pattern = new Regex(@"^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$");
        Match match = pattern.Match(value);
        if (match.Success == false) return false;
        return true;
    }

Answer 4

Simply prepend http:// if it's not there and then test.

if (inputURL.substring(0,7) != 'http://' && inputURL.substring(0,8) != 'https://') {
    inputURL = 'http://' + inputURL;
}

No large libraries required or anything, just a few lines of code.