Find if a String is present in an array [duplicate]

Question

This question already has answers here:

How do I determine whether an array contains a particular value in Java? (33 answers)

Closed 8 years ago.

OK let's say I have an array filled with {"tube", "are", "fun"} and then I have a JTextField and if I type either one of those commands to do something and if NOT to get like a message saying "Command not found".

I tried looking in Java docs but all I am getting is things that I don't want like questions and stuff... so, how is this done? I know there is a "in array" function but I'm not too good with combining the two together.

Thanks.

Here is what I have so far:

String[] dan = {"Red", "Orange", "Yellow", "Green", "Blue", "Violet", "Orange", "Blue"};
boolean contains = dan.contains(say.getText());

but I am getting cannot find symbol in dan.contains

Answer 1

This is what you're looking for:

List<String> dan = Arrays.asList("Red", "Orange", "Yellow", "Green", "Blue", "Violet", "Orange", "Blue");
boolean contains = dan.contains(say.getText());

If you have a list of not repeated values, prefer using a Set<String> which has the same contains method

• Pablo Fernandez: That's because an array is not a set
• Stephen C: @Dan - BZZZT - you are trying to invoke contains on an array, not a Set!!!
• test: THANKS SIMPSO- I MEAN PABLO! :D Tahnks Stephen. Rookie mistake.

Answer 2

String[] a= {"tube", "are", "fun"};
Arrays.asList(a).contains("any");

• ether_joe: THIS is what I was looking for. Simple !

Answer 3

Use Arrays.asList() to wrap the array in a List<String>, which does have a contains() method:

Arrays.asList(dan).contains(say.getText())

Answer 4

This can be done in java 8 using Stream.

import java.util.stream.Stream;
String[] stringList = {"Red", "Orange", "Yellow", "Green", "Blue", "Violet", "Orange", "Blue"};
boolean contains = Stream.of(stringList).anyMatch(x -> x.equals(say.getText());

• John Henckel: This is the best answer. The others fail because asList returns non-parameterized generic.

Answer 5

If you can organize the values in the array in sorted order, then you can use Arrays.binarySearch(). Otherwise you'll have to write a loop and to a linear search. If you plan to have a large (more than a few dozen) strings in the array, consider using a Set instead.

• test: Erm, would it matter if I said that the array would be permnant and not changed at a order at all? Would there be an easier way than?
• Stephen C: @Dan - I think his first sentence answers that. You do know how to sort strings by hand, don't you?
• Aleksandar Dimitrov: @Jim, this answer is incorrect. The documentation of #binarySearch explicitly states: "If the array contains elements that are not mutually comparable (for example, strings and integers), it cannot be sorted according to the natural ordering of its elements, hence results are undefined." DO NOT use binarySearch on Integer or String, or any elements that can at most have a partial order.