Manipulating the URL via strings

string_url.js

let url = 'https://host.test/path/here.filetype?query=string&more=params#anchor';
const querystringStart = url.indexOf('?');
const anchorStart = url.indexOf('#');
const querystring = url.slice(querystringStart + 1, anchorStart);
let querystringParams = querystring.split('&');
let newQuerystringParams = [];
querystringParams.forEach((queryparam, i) => {
  let param = queryparam.split('=');
  if (param[0] !== 'more') {
    newQuerystringParams.push(`${param[0]}=${param[1]}-changed`)
  }
});
newQuerystringParams.push('new=param')
const newQuerystring = newQuerystringParams.join('&');
const newUrl = `${url.slice(0, querystringStart)}?${newQuerystring}${url.slice(anchorStart)}`;