将url参数转为json对象

/**
 * 将url参数转为json对象
 *
 * @param str
 * @returns {{}}
 */
function parseQueryString(str){
    arr = [],
    length = 0,
    res = {};
    arr = str.split('&');
    length = arr.length;
    for(var i=0; i<length-1; i++){
        res[arr[i].split('=')[0]] = arr[i].split('=')[1];
    }
    return res;
}