If I call methodA and then methodB output is: "121234". But I need output: "1234", "12" from methodA and "34" from methodB. I need to remember where getNumber ended with the return, and the next call continue from here. It is possible?
MethodA snipset
int x = 0;
foreach (var num in GetNumber())
{
if (x == 2)
{
break;
}
x++;
Console.Write(num);
}
MethodB snipset
int x = 0;
foreach (var num in GetNumber())
{
if (x == 4)
{
break;
}
x++;
Console.Write(num);
}
GetNumber
static IEnumerable<int> GetNumber()
{
int x = 0;
while (true)
{
yield return x++;
}
}
You can initialize x
outside the method:
static class InfiniteContinuingSequence
{
static int x = 0;
public static IEnumerable<int> GetNumbers()
{
while (true)
{
yield return x++;
}
}
}
But you will have to explicitly be careful when and where this sequence gets enumerated. If it is inadvertently enumerated multiple times, you will "lose" numbers in the sequence; if you try to exhaustively enumerate GetNumbers()
you'll get either an infinite loop or an overflow; and if you try to call this from multiple threads without locking, you'll get potentially odd behavior.
Instead, I might suggest to either use an explicit enumerator, or be able to specify a "restart point" to your method (in this case at least you will not get odd behavior by multiple enumerations):
static IEnumerable<int> GetNumbers(int startingPoint = 0)
{
int x = startingPoint;
while (true)
{
yield return x++;
}
}
Change GetNumber
to
static int x = 0;
static IEnumberable<int> GetNumber()
{
while (true) { yield return x++; }
}
The issue is that you have two enumerations of GetNumber. By making x
static you will get the results you want. But beware this is not thread safe
code.
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