Iterating through array - java

You should definitely encapsulate this logic into a method.

There is no benefit to repeating identical code multiple times.

Also, if you place the logic in a method and it changes, you only need to modify your code in one place.

Whether or not you want to use a 3rd party library is an entirely different decision.

Since atleast Java 1.5.0 (Java 5) the code can be cleaned up a bit. Arrays and anything that implements Iterator (e.g. Collections) can be looped as such:

public static boolean inArray(int[] array, int check) {
   for (int o : array){
      if (o == check) {
         return true;
      }
   }
   return false;
}

In Java 8 you can also do something like:

// import java.util.stream.IntStream;

public static boolean inArray(int[] array, int check) {
   return IntStream.of(array).anyMatch(val -> val == check);
}

Although converting to a stream for this is probably overkill.

You can import the lib org.apache.commons.lang.ArrayUtils

There is a static method where you can pass in an int array and a value to check for.

contains(int[] array, int valueToFind) Checks if the value is in the given array.

ArrayUtils.contains(intArray, valueToFind);

ArrayUtils API

If you are using an array (and purely an array), the lookup of "contains" is O(N), because worst case, you must iterate the entire array. Now if the array is sorted you can use a binary search, which reduces the search time to log(N) with the overhead of the sort.

If this is something that is invoked repeatedly, place it in a function:

private boolean inArray(int[] array, int value)
{  
     for (int i = 0; i < array.length; i++)
     {
        if (array[i] == value) 
        {
            return true;
        }
     }
    return false;  
}