Using IEnumerable without foreach loop

Question

I\'ve gotta be missing something simple here.

Take the following code:

public IEnumerable getInt(){
  for(int i = 0; i < 10; i++){
   y         


        

Answer 1

Sample,

public static void SampleIteratorNext()
{
    var beauty = BeautifulLadies().GetEnumerator();

    Console.WriteLine($"Friday with {Next(beauty)} ...");
    Console.WriteLine($"Saturday with {Next(beauty)} ...");
    Console.WriteLine($"Tusday with {Next(beauty)} ...");
}

public static IEnumerable<string> BeautifulLadies()
{
    yield return "Scarlett";
    yield return "Alexandra";
    yield return "Alisson";
}

// emulate next() in python
public static T Next<T>(IEnumerator<T> iterator)
{
    iterator.MoveNext();
    return iterator.Current;
}

Answer 2

Although the accepted answers are correct, notice that IEnumerator.Current is undefined before the first call to MoveNext().

If you are iterating over a secondary array, you'll want something like:

IEnumerable<Foo> Foo() { ... }

int AssignValues(List<TakesFoo> data) {
  var count = 0;
  var foo = Foo().GetEnumerator();

  // Step into the first element of the array;
  // doing this does not discard a value from the IEnumerator
  if (foo.MoveNext()) { 
    foreach (var x in data) {
      x.SetFoo(foo.Current);
      count += 1;
      if (!foo.MoveNext()) { 
        break;
      }
   }

   // Return count of assigned values
   return count;
}

Answer 3

using for loop:

for (var enumerator = getInt().GetEnumerator(); enumerator.MoveNext(); )
{
    Console.WriteLine(enumerator.Current);
}

Answer 4

How about this?

IEnumerator<int> iter = obj.getInt();
using(iter) {
    while(iter.MoveNext()) {
        DoSomethingWith(iter.Current)
    }
}

Answer 5

It's important to mention that the duty of the foreach loop is to dispose the enumerator if the instance implements IDisposable. In other words, foreach should be replaced with something like:

var enumerator = enumerable.GetEnumerator();

try
{
    while (enumerator.MoveNext())
    {
        var item = enumerator.Current;
        // do stuff
    }
}
finally
{
    var disposable = enumerator as IDisposable;
    if (disposable != null)
    {
        disposable.Dispose();
    }
}

Answer 6

You can get a reference to the Enumerator, using the GetEnumerator method, then you can use the MoveNext() method to move on, and use the Current property to access your elements:

var enumerator = getInt().GetEnumerator();
while(enumerator.MoveNext())
{
    int n = enumerator.Current;
    Console.WriteLine(n);
}