You mean fast enumeration? You question is very unclear.
A normal for loop would look a bit like this:
unsigned int i, cnt = [someArray count];
for(i = 0; i < cnt; i++)
{
// do loop stuff
id someObject = [someArray objectAtIndex:i];
}
And a loop with fast enumeration, which is optimized by the compiler, would look like this:
for(id someObject in someArray)
{
// do stuff with object
}
Keep in mind that you cannot change the array you are using in fast enumeration, thus no deleting nor adding when using fast enumeration