Question

angularjs ng-repeat可以含有表达式吗

Answer 1

angularjs ng-repeat可以含有表达式track by.
<div ng-repeat="links in slides">
<div ng-repeat="link in links track by $index">{{link.name}}</div>
</div>

Error: [ngRepeat:dupes]这个出错提示具体到题主的情况，意思是指数组中有2个以上的相同数字。ngRepeat不允许collection中存在两个相同Id的对象
For example: item in items is equivalent to item in items track by $id(item). This implies that the DOM elements will be associated by item identity in the array.
对于数字对象来说，它的id就是它自身的值，因此，数组中是不允许存在两个相同的数字的。
为了规避这个错误，需要定义自己的track by表达式。
例如：item
in items track by item.id或者item in items track by fnCustomId(item)。
也可以，直接拿循环的索引变量$index来用item。

Answer 2

下面分析两个经典面试题。
l 例1：
class A
{
protected:
int m_data;
public:
A(int data = 0)
{
m_data = data;
}
int GetData()
{
return doGetData();
}
virtual int doGetData()
{
return m_data;
}
};
class B: public A
{
protected : int m_data;
public:
B(int data = 1)
{
m_data = data;
}
int doGetData()
{
return m_data;
}
};
class C : public B
{
protected : int m_data;
public :
C(int data = 2)
{
m_data = data;
}
};
int _tmain(int argc, _TCHAR* argv[])
{
C c(10);
cout<<c.GetData() << endl; //1
cout<<c.A::GetData()<<endl; //1
cout<<c.B::GetData()<<endl; //1
cout<<c.C::GetData()<<endl; //1
cout<<c.doGetData()<<endl; //1
cout<<c.A::doGetData()<<endl; //0
cout<<c.B::doGetData()<<endl; //1
cout<<c.C::doGetData()<<endl; //1
return 0;
}