截取url参数

function urlToObj(str) {
  var obj = {};
  var arr1 = str.split("?");
  var arr2 = arr1[1].split("&");
  for (var i = 0; i < arr2.length; i++) {
    var res = arr2[i].split("=");
    obj[res[0]] = res[1];
  }
  return obj;
}