How can I extract Id from a URL using Javascript?

var myurl = 'http://localhost:9080/company_add.jsp?id=254162';
console.log(myurl.replace(new RegExp(/.*id=(\d+)(\D.*)?/, ""), '$1'));

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Output:

254162

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The regular expression works by looking at 3 parts of the URL:
1. the part up to and including id=
2. a number
3. everything after the number, if anything.

The replace command replaces the lot with just the value from 2. above. This is done by putting brackets around the part of the pattern used to match the number, which captures it as $1. It can then be used as the replacement for the whole string.

Another alternative not using Regex - gets the parameters into an Object

<script>
var inp = ' http://localhost:9080/company_add.jsp?id=254162&a=fred&b=donky&c=adsf09afua0ufa';

function getUrlParams(url) 
{
  var temp = url.split('?');
  var result = {}
  if (temp[1]) {  
    var params = temp[1].split('&');
    for(var i = 0; i < params.length; i++) {
      var t = params[i].split('=');
      result[t[0]] = t[1]
    }
  }
  return result;
}

var params = getUrlParams(inp);
if (params.id) console.log(params.id);
</script>

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Thank  you@Julian,  @Terry and @Hielo.I  did  decide  to  go with  Terry solutions but facing issue  with  regex  expression.I have tried to  test  regex expression on  regex101.com, with no  issue.Am I missing anything here(i.e I did  try to type on keyboard as well instead of copy-paste)?below is  the error under F12 tools on  internet  explorer   v11

One thing: I see

 var url=window.location.pathname

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is returned as "/company_view.jsp"  after I  did  console.log.I want to  return a complete current url which is http://localhost:9080/company_add.jsp?id=254162

Now I  was able to  return the  URL by

var url=window.location.href

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; but the  regex  failed  with the same error

The solution you are using does a replace - I thought you wanted to do an extract which would require a match

<script>
var url = window.location.href;
var result = url.match(/id=(\d+)/);
var id = result ? result[1] : false;
console.log(result);
</script>

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Thank  you@Julian...it works :)

You are welcome.