How can I verify that an array of strings contain a certain string?

java arrays string compare
JAN picture JAN · Feb 2, 2012 · Viewed 79k times · Source

Given : 

String[] directions = {"UP","DOWN","RIGHT","LEFT","up","down","right","left"};

String input = "Up";

How can I verify that an input from stdin is within the directions array or not ?

I can make a loop and check each item with input using equal ,but I'm looking for a more elegant way.

Regards,Ron

Answer

mikej picture mikej · Feb 2, 2012

Convert the array of valid directions to a list:

List valid = Arrays.asList(directions)

Or just declare it directly as:

List valid = Arrays.asList("UP", "DOWN", "RIGHT", "LEFT", "up", "down", "right", "left")

You can then use the contains method:

if (valid.contains(input)) {
    // is valid
} else {
    // not valid
}

Note that this won't match a mixed case input such as "Up" so you might want to store just the uppercase values in the list and then use valid.contains(input.toUpperCase())

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