I have two lists of objects. List A and List B. I need to create List C which combines List A and List B into pairs. For example:
List A
object a1
object a2
object a3
List B
object b1
object b2
object b3
List C (creates pairs)
object c1 (object a1, object b1)
object c2 (object a2, object b2)
object c3 (object a3, object b3)
This would do it:
public static IEnumerable<Tuple<T, U>> CombineWith<T, U>(this IEnumerable<T> first, IEnumerable<U> second)
{
using (var firstEnumerator = first.GetEnumerator())
using (var secondEnumerator = second.GetEnumerator())
{
bool hasFirst = true;
bool hasSecond = true;
while (
// Only call MoveNext if it didn't fail last time.
(hasFirst && (hasFirst = firstEnumerator.MoveNext()))
| // WARNING: Do NOT change to ||.
(hasSecond && (hasSecond = secondEnumerator.MoveNext()))
)
{
yield return Tuple.Create(
hasFirst ? firstEnumerator.Current : default(T),
hasSecond ? secondEnumerator.Current : default(U)
);
}
}
}
Edit: I vastly prefer Paul's answer.