采用ng-repeat循环发生错误时，如下面的输出对象：
Duplicates in a repeater are not allowed. Use 'track by' expression to specify unique keys. Repeater: c in shopCount, Duplicate key: undefined:undefined
应该在循环是加下面代码 ng-repeat item in items track by $index
版权声明：本文博主原创文章。博客，未经同意不得转载。