Javascript验证域点com

Question

im trying to make a javascript input validator.

I want to check the input if its in the correct domain format. It must check the specific input when the submit button is pressed.

If it is not the correct format, the form will not submit. I am not sure with my RegExp format. Also not sure with the whole code if it will run depending on how i wanted it to be.

Here's my code :

var x1=document.forms["leform"]["domain"].value;
 validomain(x1);
function validomain(les) {
    var tdomain = new RegExp('/[:alpha:]+/./[:alpha:]+/');
    if(!tdomain.test(les)){
        alert('not a valid domain format');
        return false;
    }
}

Answer 1

Try

var tdomain = /^[\w-]+\.\w+$/;

\\w are word characters.

The . is special (matches any character) and must be escaped.

Also, you might want to research what a valid domain can look like. (Want to match subdomains? what about domains with international characters?)

Answer 2

based on your comment:

examp.le any small letter(probably max 20 chars) dot any small latter again (max 4 chars)

var x1=document.forms["leform"]["domain"].value;
 validomain(x1);
function validomain(les) {
    if ( !String(les).match(/^[a-z]{1,20}\.[a-z]{1,4}$/) ) {
        alert('not a valid domain format');
        return false;
    }
}

Answer 3

you can try this regex too:

function validomain(les) {
   var pattern = new RegExp(/([a-z0-9-]+\.(?:com))(?:\/|$)/)
   if(!pattern.test("les"))'{
      alert('not a valid domain format');
      return false;
   }
}

@Crayon Violent is right may be you have a problem elsewhere in your code