You are removing the item during a foreach, yes? Simply, you can’t. There are a few common options here: use List<T> and RemoveAll with a predicate iterate backwards by index, removing matching items for(int i = list.Count – 1; i >= 0; i–) { if({some test}) list.RemoveAt(i); } use foreach, and put matching items into … Read more
(This answer shows one of many options. Just because is has had acceptance mark, doesn’t mean it is the best one. I suggest reading other answers and picking one depending on situation you are in. IMO: for Java 8 Holger’s answer is nicest, because aside from being simple it doesn’t require additional iteration which happens … Read more
Edit: this all changes in C# 5, with a change to where the variable is defined (in the eyes of the compiler). From C# 5 onwards, they are the same. Before C#5 The second is safe; the first isn’t. With foreach, the variable is declared outside the loop – i.e. Foo f; while(iterator.MoveNext()) { f … Read more
Iterating means repeating some steps, while enumerating means going through all values in a collection of values. So enumerating usually requires some form of iteration. In that way, enumerating is a special case of iterating where the step is getting a value from a collection. Note the “usually” – enumerating may also be performed recursively, … Read more
The stop argument to the Block allows you to stop the enumeration prematurely. It’s the equivalent of break from a normal for loop. You can ignore it if you want to go through every object in the array. for( id obj in arr ){ if( [obj isContagious] ){ break; // Stop enumerating } if( ![obj … Read more
In Swift 2 this is quite easy using enumerate and reverse. var a = [1,2,3,4,5,6] for (i,num) in a.enumerate().reverse() { a.removeAtIndex(i) } print(a)
This is a hard problem indeed. One of the things you need to do is tell java that you are using an enum. This is by stating that you extend the Enum class for your generics. However this class doesn’t have the values() function. So you have to take the class for which you can … Read more
The collection used in foreach is immutable. This is very much by design. As it says on MSDN: The foreach statement is used to iterate through the collection to get the information that you want, but can not be used to add or remove items from the source collection to avoid unpredictable side effects. If … Read more
The best solution is usually to use the RemoveAll() method: myList.RemoveAll(x => x.SomeProp == “SomeValue”); Or, if you need certain elements removed: MyListType[] elems = new[] { elem1, elem2 }; myList.RemoveAll(x => elems.Contains(x)); This assume that your loop is solely intended for removal purposes, of course. If you do need to additional processing, then the … Read more
There’s not really a good way to do this, usually you see an extra item in the enum, i.e. enum foobar {foo, bar, baz, quz, FOOBAR_NR_ITEMS}; So then you can do: int fuz[FOOBAR_NR_ITEMS]; Still not very nice though. But of course you do realize that just the number of items in an enum is not … Read more