Generally you should only use enumeration where there is a clear set of items that will not change, e.g. primary colours, or continent names. Otherwise lookup tables with appropriately implemented foreign keys are pretty much always the best option. There is a possible variation on the lookup table option where you potentially have a large …
Differences: Enums extend java.lang.Enum and gain all of its nice features: Automatic singleton behaviour through correct serialization Automatic human-readable .toString method on enum values without the need to duplicate your enum names .name and .ordinal special-purpose methods Usable in high-performance bitset-based EnumSet and EnumMap classes Enums are treated by the language specially: Enums use a …
You should replace your getEnumNameForValue by a call to the name() method.
Per that standard [dcl.enum] The enumeration type declared with an enum-key of only enum is an unscoped enumeration, and its enumerators are unscoped enumerators. The enum-keys enum class and enum struct are semantically equivalent; an enumeration type declared with one of these is a scoped enumeration, and its enumerators are scoped enumerators. The optional identifier …
As an easy and clean way of using an Enumeration with the enhanced for loop, convert to an ArrayList with java.util.Collections.list. for (TableColumn col : Collections.list(columnModel.getColumns()) { (javax.swing.table.TableColumnModel.getColumns returns Enumeration.) Note, this may be very slightly less efficient.
You call nextElement() twice in your loop. This call moves the enumeration pointer forward. You should modify your code like the following: while (e.hasMoreElements()) { String param = e.nextElement(); System.out.println(param); }
In python, using locals which returns a dictionary containing all the local bindings, thus, avoiding eval: >>> foo1 = “Hello world” >>> foo2 = “bar” >>> foo3 = {“1″:”a”, … “2”:”b”} >>> foo4 = “1+1” >>> import pprint >>> pprint.pprint(locals()) {‘__builtins__’: <module ‘__builtin__’ (built-in)>, ‘__doc__’: None, ‘__name__’: ‘__main__’, ‘foo1’: ‘Hello world’, ‘foo2’: ‘bar’, ‘foo3’: {‘1’: …
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 …
(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 …
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 …