查詢字符串轉換成key: value格式獲取

/**
 * @desc 將查詢字符串轉換成key: value的形式
 * @param {string} query - 查詢字符串 '?a=chenfeng&b=ami&c=&d=999';
 * @returns {object}
 */
function getQueryMap(query) {
  var queryMap = {};
  query.substr(1) // 截去 '?'
       .split('&') // 轉換成['a=chenfeng', 'b=ami']
       .forEach(item => {
         const [key, value] = item.split('='); // ['a', 'chenfeng']
         queryMap[key] = value;
       });

  return queryMap;
}

// { a: 'chenfeng', b: 'ami', c: '', d: '999' }
console.log(getQueryMap('?a=chenfeng&b=ami&c=&d=999'));