Question

JS解析JSON字符串

var result={"Category":[{"categoryId":1,"categoryName":"饮品","categoryImage":"/upload/yinpin.jpg"},{"categoryId":2,"categoryName":"食品","categoryImage":"/upload/shiping.jpg"},{"categoryId":3,"categoryName":"酒类","categoryImage":"/upload/jiullei.jpg"}],
"recommend":{"id":11,"productName":"统一
老坛泡椒牛肉袋面香辣味
110g*24袋","filenameSmall":"/upload/ty_ltpj_small.jpg","productPrice":48.0,"productCost":47.5}}

var json=JSON.parse(result);
alert(json.Category.categoryName); 这个弹出框显示该值未定义
为什么？应该怎么取到这个值

Answer 1

var result={"Category":[{"categoryId":1,"categoryName":"饮品","categoryImage":"/upload/yinpin.jpg"},{"categoryId":2,"categoryName":"食品","categoryImage":"/upload/shiping.jpg"},{"categoryId":3,"categoryName":"酒类","categoryImage":"/upload/jiullei.jpg"}],"recommend":{"id":11,"productName":"统一老坛泡椒牛肉袋面香辣味110g*24袋","filenameSmall":"/upload/ty_ltpj_small.jpg","productPrice":48.0,"productCost":47.5}};
var val = result.Category[0].categoryId;

这样就能得到值了啊

你的代码失效的原因有两个：

1、result已经是JSON格式的数据了，所以不需要再次用JSON.parse(result)进行转换

2、result.Category是个数组，所以要用[0]来取出某一项的值