Q3PtrListIterator Class Reference
[Qt3Support module]

Detailed Description

The Q3PtrListIterator class provides an iterator for Q3PtrList collections.

Define a template instance Q3PtrListIterator<X> to create a list iterator that operates on Q3PtrList<X> (list of X*).

The following example is similar to the example in the Q3PtrList class documentation, but it uses Q3PtrListIterator. The class Employee is defined there.

 Q3PtrList<Employee> list;

 list.append( new Employee("John", "Doe", 50000) );
 list.append( new Employee("Jane", "Williams", 80000) );
 list.append( new Employee("Tom", "Jones", 60000) );

 Q3PtrListIterator<Employee> it( list );
 Employee *employee;
 while ( (employee = it.current()) != 0 ) {
     ++it;
     cout << employee->surname().latin1() << ", " <<
             employee->forename().latin1() << " earns " <<
             employee->salary() << endl;
 }

The output is

 Doe, John earns 50000
 Williams, Jane earns 80000
 Jones, Tom earns 60000

Using a list iterator is a more robust way of traversing the list than using the Q3PtrList member functions first(), next(), current(), etc., as many iterators can traverse the same list independently.

An iterator has its own current list item and can get the next and previous list items. It doesn't modify the list in any way.

When an item is removed from the list, all iterators that point to that item are updated to point to Q3PtrList::current() instead to avoid dangling references.

See also Q3PtrList.

Member Function Documentation