Constructing an if statement that checks enums on a list

Question

What would be the most efficent to check if something is on a list of enums? I've looked around for a while and it wasn't very clear. Arrays don't have a contains() function and hashmaps are key:value.

Something like:

if(enumlist.contains(foo.enum())){
    // Do something
}

Answer 1

Use List#indexOf().

if (enumList.indexOf(foo) > -1) {
    // go crazy
}

Alternately, you can use the (extremely efficient) EnumSet data structure to store the objects — if you're okay with not being able to store duplicate elements.

if (enumSet.contains(foo)) {
    // just, like, whatever, man
}

Answer 2

EnumSet has a suitable contains() method.

Addendum: Using this example, the following prints true.

System.out.println(Resolution.deluxe.contains(Resolution.RES_256));