public class LinearSearch {
    public static void main(String[] args) {
        int[] arr = new int[5];
        for(int i=0;i<arr.length;i++) {
            arr[i]=i;
        }
        int target = 2;
        System.out.println("element found in the array at index " +linearSearch(arr, target));
        int targetNotInArray = 100; // to prove worst case
        System.out.println("This will iterate through the array and element "
                + "is not found in array and return false" +
        linearSearch(arr, targetNotInArray));
    }

    static int linearSearch(int[] arr, int target) {
        if (arr.length == 0) { // if the array has no element
            return -1;
        }
        // looping through the array to find element
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] == target) {
                return i;
            }
        }

        return -1;
    }
}