获取 url 中的参数 about fd-interview HOT 1 OPEN

function getQueryParam (url, name) {
  url = decodeURIComponent(url);
  let query = url.split('?')[1];
  if(!query) return '';
  query = query.slice(0).split('&');
  let paramObj = query.reduce(function(prev, next) {
    next = next.split('=');
    if(prev[next[0]]) {
      if(!Array.isArray(prev[next[0]])) prev[next[0]] = [prev[next[0]]];
      prev[next[0]].push(next[1]);
    } else {
      prev[next[0]] = next[1];
    }
    return prev;
  }, {})
  if(!name) return paramObj;
  return paramObj[name] || '';
}