What are the differences between a Java enum and a class with private constructor? [duplicate]

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 …

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Do C++ enums Start at 0?

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 …

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Why aren’t Enumerations Iterable?

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.

Enumerate or list all variables in a program of [your favorite language here] [closed]

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’: …

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Collection was modified; enumeration operation may not execute in ArrayList [duplicate]

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 …

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