Just do it like this:
You have to do a little error handling for non existent elements there:
public static void main(String[] args) throws IOException {
int[] inputArray = new int[] {1, 2, 3, 4, 5, 6,7};
int siblingsToFindOf = 6;
int[] results = findSiblings(inputArray.length, inputArray, siblingsToFindOf);
for(int i=0;i<results.length;i++){
System.out.print(String.valueOf(results[i]) + ",");
}
}
public static int[] findSiblings(int input1, int[] input2, int input3) {
int[] result = new int[] {-1};
if (input2[0] == input3) {
return result;
}
int siblingFindIndex = -1;
for(int i=0;i<input2.length;i++){
if(input2[i]==input3) {
siblingFindIndex = i;
break;
}
}
if(siblingFindIndex>-1){
result = new int[]{input2[siblingFindIndex-1],input2[siblingFindIndex+1]};
}
return result;
}