如何读取到json数据里的这个项

Question

在js里模拟了一段json数据，为什么读取不出来这个啊，总说未定义。var jsonObj = {    "name" : "市级和地区",    "total"  : [         {            "city":["大兴区","东城区","西城区"],            "area":[                 ["一号街","二号街","三号街"],                 ["四号街","五号街","六号街"],                 ["七号街","八号街","九号街"]             ]         } }console.log(jsonObj.total[0].area.length);//报错 说area未定义写成console.log(jsonObj.total0.area.length); //还是不行可是：console.log(jsonObj.total[0].city.length); //就可以行得通求助 谢谢