访问容器内元素的成员函数

[alexandnpu]

#include <iostream>
#include <list>

using std::cout;
using std::endl;
using std::list;

class object
{
public:
	object();
	object(int v);
	object(object &a);
	virtual ~object();
	
	int getData();
	void setData(int v);
private :
	int data;
};

object::object()
{
	this->data = 0;
}
object::object(int v)
{
	this->data = v;
}
object::object(object &a)
{
	this->data = a.getData();
}
object::~object()
{}
int object::getData()
{
	return this->data;
}
void object::setData(int v)
{
	this->data = v;
}











int main(int argc, char **argv)
{
	int array[] = {1,4,2,5,8,4};
	list<int> lt(array, array + sizeof(array) / sizeof(int));
	
	list<object*> test(10);
	object first(4);
	object second(2);
	object third(8);
	
	test.push_back(&first);
	test.push_back(&second);
	test.push_back(&third);
	
	for(list<object*>::iterator iter = test.begin(); iter != test.end(); ++iter)
	{
		cout << (*iter)->getData() << endl;
	}
	return 0;
}

代码如上，我的想法就是访问通过iter遍历这个容器来访问其中的成员函数？
为什么出错呢？这几天有点糊涂，上来问问大侠们，多谢了

[clyu1981]

(*iter)->getData() 这句好像有问题。

[wwq100]

迭代器解引用

[deng1243]

#include <iostream>
#include <list>

using namespace std;

class object
{
public:
    object();
    object(int v);
    object(object &a);
    virtual ~object();
    
    int getData();
    void setData(int v);
private :
    int data;
};

object::object()
{
    this->data = 0;
}
object::object(int v)
{
    this->data = v;
}
object::object(object &a)
{
    this->data = a.getData();
}
object::~object()
{}
int object::getData()
{
    return this->data;
}
void object::setData(int v)
{
    this->data = v;
}

int main(int argc, char **argv)
{
    int array[] = {1,4,2,5,8,4};
    list<int> lt(array, array + sizeof(array) / sizeof(int));
    
    list<object*> test;//mark
    object first(4);
    object second(2);
    object third(8);
    
    test.push_back(&first);
    test.push_back(&second);
    test.push_back(&third);
    
    for(list<object*>::iterator iter = test.begin(); iter != test.end(); ++iter)
    {
        cout << (*iter)->getData() << endl;
    }
    return 0;
}

[deng1243]

一开始list<object*>::iterator iter = test.begin();
(*iter)->getData() 访问的是未知内存

[j2meme]

关注，学习

[pady_pady]

list<object*> test(10);
改为list<object*> test;
不然前面十个指针为野指针
或者改这里
for(list<object*>::iterator iter = test.begin() + 10; iter != test.end(); ++iter)

[zhou1xp]

mark

[macrojj]

list<object*> test(10);
这样是已经分配了内存。要往已经分配的里面赋值 要用[]
pushback是新分配的。所以你前面10个都不知道向哪个地址止的

[herry-Li]

[Quote=引用 5 楼 j2meme 的回复:]
关注，学习
[/Quote]


此仁兄说的很对

[herry-Li]

[Quote=引用 6 楼 pady_pady 的回复:]
list <object*> test(10);
改为list <object*> test;
不然前面十个指针为野指针
或者改这里
for(list <object*>::iterator iter = test.begin() + 10; iter != test.end(); ++iter)
[/Quote]

此仁兄说的很对

[elegant87]

//iterator 就相当于指针，用之前必须进行初始化
int main(int argc, char **argv)
{
    int array[] = {1,4,2,5,8,4};
    list<int> lt(array, array + sizeof(array) / sizeof(int));
    
   // list<object*> test(10);//此处说明定义10个object的指针，并没有赋值 
   //修改如下
    object obj(100);
    list<object*>test(10,&obj); 
    object first(4);
    object second(2);
    object third(8);
    
    test.push_back(&first);
    test.push_back(&second);
    test.push_back(&third);
    
    for(list<object*>::iterator iter = test.begin(); iter != test.end(); ++iter)
    {
        cout << (*iter)->getData() << endl;
    }
    system("pause");
    return 0;
}

[yunyun050924]

不懂，解引用就可以用点操作符调用了吧