Qt中foreach的用法

Qt中foreach的用法

 

 

If you just want to iterate over all the items in a container in order, you can use Qt'sforeach keyword. The keyword is a Qt-specific addition to the C++ language, and is implemented using the preprocessor.

Its syntax is: foreach (variable, container)statement. For example, here's how to use foreach to iterate over aQLinkedList<QString>:

 QLinkedList<QString> list; ... QString str; foreach (str, list) qDebug() << str;

如果你想有序迭代容器中的所有项可以使用关键字foreach，这是qt对C++的特定补充，并通过预处理器实现。他的语法是：foreach (variable, container) +语句；这儿varible就相当于varible=container.item,只不过这个item会从container的头遍历到尾罢了。

 QLinkedList<QString> list;

 QLinkedListIterator<QString> i(list); while (i.hasNext()) qDebug() << i.next();

这两个语句达到的目的是一样的