cocos2dx3.0 transition of various traversal and scope for statements using "go"

1, Ccarray of the traversal
See here, some people also press can not endure to raise watermelon knife: You do not say after 3.0beta has no ccarray this goods? What are you doing now?
In fact, I am also very innocent,Ccarray really is not, but in some unknown corner but hidden __array this goods, I dare to guess it is ccarray half brother, because it has and ccarray the same function. Unfortunately, because of the rise of vectors, __array is doomed to be buried.

Ccarray's traversal macro is Ccarray_foreach (_array,_object), which is the way to traverse, with a for statement to explain the beginning of the int i=0. Use the following:

View Sourceprint? 01. auto sp = Sprite::create( "close.png" ); //建立俩精灵 02. sp->setPosition(Point( 200 , 300 )); 03. this ->addChild(sp, 2 ); 04.  05. auto sp2 = Sprite::create( "close.png" ); 06. sp2->setPosition(Point( 300 , 300 )); 07. this ->addChild(sp2, 2 ); 08.  09. __Array* m_array = __Array::create(); //用__Array创建一个数组 10. m_array->addObject(sp); //将sp与sp2放入数组中 11. m_array->addObject(sp2); 12.  13. Ref* obj = nullptr; 14. CCARRAY_FOREACH(m_array,obj) 15. { 16. auto sp_obj = static_cast<Sprite*>(obj); //将obj强制转换成Sprite 17. sp_obj->runAction(MoveBy::create( 3 .0f,Point( 250 , 250 ))); //运动 18. }

Of course, some people like the more exciting way to come from behind! Is there such a traversal? Of course, Ccarray_foreach_reverse (_array,_object) satisfies all your fantasies. in the words of SB.: From the back. Pain! Fast!. Is that really so much fun? Just try it and know it (if you want to have a girlfriend ...) Strange, why do I talk about girlfriends?? ）。

2, ccdictionary of the traversal
I beg you again to put down the angry watermelon knife in your hand! If Ccarray and __array are half-mother, then Ccdictionary and __dictionary are the same!
ccdictionary Traverse macro: Ccdict_foreach (_dic,_ele), use the following:

View Sourceprint? 01. __Dictionary* dic = __Dictionary::create(); 02. dic->setObject(sp, "sp" ); //将sp与sp2放入字典中，键分别为sp与sp2 03. dic->setObject(sp2, "sp2" ); 04.  05. DictElement* ele; 06. CCDICT_FOREACH(dic,ele) 07. { 08. auto sp_obj = static_cast<Sprite*>(ele->getObject()); //将ele强制转换成Sprite 09. sp_obj->runAction(MoveBy::create( 3 .0f,Point( 250 , 250 ))); 10. }

3, vector "traversal"
The traversal of a vector involves c++11, and a relationship with C + + 11 means that the code can be written in a simpler, less reliable way. Look underneath.

View Sourceprint? 1. Vector<Sprite*> sp_vec; //创建一个容器 2. sp_vec.pushBack(sp); //将俩精灵扔进去 3. sp_vec.pushBack(sp2); 4.  5. for ( auto sp_obj : sp_vec) 6. { 7. sp_obj->runAction(MoveBy::create( 3 .0f,Point( 250 , 250 ))); //每次for循环都从sp_vec容器中取出一个精灵 8. }

One step, there are wood! if the use of vectors is not very familiar with children's shoes, poke here : http://blog.csdn.net/start530/article/details/19170853

4. "Traversal" of map
It is similar to the way vectors are traversed, but there are some things that are different:

View Sourceprint? 01. Map<std::string,Sprite*> sp_map; //创建一个Map容器，键值分别为string型与Sprite类型 02. sp_map.insert( "sp" ,sp); //将sp扔进去， 03. sp_map.insert( "sp2" ,sp2); 04.  05. for ( auto e : sp_map) 06. { 07. auto sp_obj = e.second; //e.first获得的是e的键值，e.second获得对象 08. sp_obj->runAction(MoveBy::create( 3 .0f,Point( 250 , 250 ))); 09. }

Not familiar with the map? Poke here: http://blog.csdn.net/start530/article/details/19284301

5. Use the range for statement

The use of vector and map above uses a new thing: the range for statement. Since it's all written here, I'll keep on talking about the words.

The scope for statement is a new statement provided by C++11, which is in the following form:
for (declaratio:expression)
{
Statement
}
Expression is an object, such as a vector, Declarationo is responsible for defining a variable that will be initialized to the next element in expression each time it is iterated.
So what types of objects can use the range for statement? At present I know can use:vector,map,std::string, there are cocos2dx in the Vector,map. These common features are the begin and end members that have the ability to return iterators.

Here's an example: Use the range for statement to output the characters in a string object one line at a std::string:

View Sourceprint? 1. std::string str( "star530 is so cool" ); 2. //每行输出str中的一个字符 3. for (auto c : str)        //对于str中的每个字符 4. cout << c << endl;   //输出当前字符，后面紧跟一个换行符

The type of C is determined by using auto (Type C is char). Each time the loop is passed, the next character of Str is copied to C.

cocos2dx3.0 transition of various traversal and scope for statements using "go"