how to check if a certain value is inside an array code example

Example 1: javascript is int in array

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(1, 2);  // false (second parameter is the index position in this array at which to begin searching)

Example 2: check if an element is already in an array

private boolean ZitAlInArray(int value, List<Integer> list) {
  return array.indexOf(value) > -1;
}

private boolean zitAlInArray(int[] array, int index) {
		for (int i = 0; i < index; i++) {
			if (array[i] == array[index]) {
				return true;
			}
		} 
		return false;
	}