Question

我需要迭代一套。该集合是一组Items，它是我实现的类。我有这个错误：

error C2662: 'double Item::getUnitPrice(void)' : cannot convert 'this' pointer from 'const Item' to 'Item &'

这是我遍历集合的函数，但我有错误＆＃34; sum + = it-＆gt; getUnitPrice（）;＆＃34;

double Customer::totalSum()
{
    double sum = 0;
    set<Item>::iterator it;

    for (it = _items.begin(); it != _items.end(); ++it)
    {
        sum += it->getUnitPrice();
    }

    return sum;
}

提前致谢！

Answer 1

你应该遍历你的集合：

double Customer::totalSum()
{
    double sum = 0f;

    for( std::set<Item>::iterator it = _items.begin(); it != _items.end(); ++it )
    {
        sum += (*it).totalPrice();
    }

    return sum;
}

Answer 2

我只是不知道如何使用套装到达unitPrice。

double Customer::totalSum()
{
    double sum = 0;
    set<Item>::iterator begin = _items.begin();   <<< Although clever compilers can make 
    set<Item>::iterator end = _items.end();      << this a futile attempt at optimization.

    for( set<Item>::iterator iter = begin; iter != end; ++iter )
    {
       sum += it->getUnitPrice();
    }
  return sum;
}

我有一个迭代集的问题

2 个答案: