In an if statement in Java how can I check whether an object exists in a set of items. E.g. In this scenario i need to validate that the fruit will be an apple, orange or banana.
if (fruitname in ["APPLE", "ORANGES", "GRAPES"]) { //Do something } It's a very trivial thing but I couldn't figure out a short and concise way to accomplish this.
static final List<String> fruits = Arrays.asList("APPLE", "ORANGES", "GRAPES"); if (fruits.contains(fruitname)) If your list was much larger, a set would be more efficient.
static final Set<String> fruits = new HashSet<String>( Arrays.asList("APPLE", "ORANGES", "GRAPES", /*many more*/)); 
Set. Seems more appropriate.
Set is the right type for the job, even if the particular implementation might not be.for completeness using google-collections/guava:
import com.google.common.collect.Sets; static final Set<String> fruit = Sets.newHashSet("APPLE", "ORANGES", "GRAPES"); if (fruit.contains(fruitname)) or using the plane old jdk classes:
static final Set<String> fruit = new HashSet<String>(Arrays.asList("APPLE", "ORANGES", "GRAPES")); Is Arrays.binarySearch what you are looking for?
String [] fruits = new String[]{"APPLE", "ORANGES", "GRAPES"}; Arrays.sort(fruits); // binarySearch requires that the array is sorted if (Arrays.binarySearch(fruits), fruitname) >= 0) { // found! } And of course the trusted Apache Commons ArrayUtils:
if (ArrayUtils.contains(new String[]{"APPLE", "ORANGES", "GRAPES"}, fruitname){ // found } I knew there would be something in Apache Commons :)
Arrays.sort is a void method, so this doesn't really compile.If you have Set, List, Map of fruits which all have the same parent: Collection, you can try this example.
String fruitName = "Orange"; Collection<String> fruits = ... // set of fruits if (fruits.contains(fruitName)) { ... } (For Java 8/9/10 ways of creating literal Set please see this SO answer.)
Be careful with case sensitivity (Orange != orange).
