JSFiddle - React, Tailwind, and code Playground

JavaScript

function RemoveParam(url, p) {
  return url
    .replace(new RegExp('[?&]' + p + '=[^&#]*(#.*)?$'), '$1')
    .replace(new RegExp('([?&])' + p + '=[^&]*&'), '$1');
}
var url='www.mydomain.com/default.aspx?param3=value3&param1=value1&param2=value2'

alert(RemoveParam(url,'param1'));