I have a nested while loop inside a foreach loop where I would like to advance the enumerator indefinitately while a certain condition is met. To do this I try casting the e
Many of the other answers recommend using continue
, which may very well help you do what you need to do. However, in the interests of showing manually moving the enumerator, first you must have the enumerator, and that means writing your loop as a while
.
using (var enumerator = times.GetEnumerator())
{
DateTime time;
while (enumerator.MoveNext())
{
time = enumerator.Current;
// pre-condition code
while (condition)
{
if (enumerator.MoveNext())
{
time = enumerator.Current;
// condition code
}
else
{
condition = false;
}
}
// post-condition code
}
}
From your comments:
How can the foreach loop advance it if it doesn't implement the IEnumerator interface?
In your loop, time
is a DateTime
. It is not the object that needs to implement an interface or pattern to work in the loop. times
is a sequence of DateTime
values, it is the one that must implement the enumerable pattern. This is generally fulfilled by implementing the IEnumerable
and IEnumerable
interfaces, which simply require T GetEnumerator()
and object GetEnumerator()
methods. The methods return an object implementing IEnumerator
and IEnumerator
, which define a bool MoveNext()
method and a T
or object Current
property. But time
cannot be cast to IEnumerator
, because it is no such thing, and neither is the times
sequence.