Linear Search:

package runnerdev; 

import java.util.Scanner; 

public class LinearSearchEx { 

     public static int linearSearch(int array[], int num) {

           int len = array.length;

           for (int i = 0; i < len; i++) {

                if (array[i] == num)

                      return i;

           }

           return -1;

     }

 

     public static void main(String args[]) {

           int array[] = { 12, 13, 40, 100, 140 };

           Scanner sc = new Scanner(System.in);

           System.out.println("Enter number : ");

           int num = sc.nextInt();

 

           int result = linearSearch(array, num);

           if (result == -1)

                System.out.print("Given number is not present in array");

           else

                System.out.print("Given number is present at index: " + result);

     }

}                                                  

 public class LinearSearch { 

       /**

        * Generic Linear search method        *

        * @param array List to be searched

        * @param value Key being searched for

        * @return Location of the key

        */

 

       public <T extends Comparable<T>> int find(T[] array, T value) {

         for (int i = 0; i < array.length; i++) {

           if (array[i].compareTo(value) == 0) {

             return i;

           }

         }

         return -1;

       }

 

       public static void main(String[] args) {

         // just generate data

         Random r = new Random();

         int size = 200;

         int maxElement = 100;

         Integer[] integers =

             Stream.generate(() -> r.nextInt(maxElement)).limit(size).toArray(Integer[]::new);

 

         // the element that should be found

         Integer shouldBeFound = integers[r.nextInt(size - 1)];

 

         LinearSearch search = new LinearSearch();

         int atIndex = search.find(integers, shouldBeFound);

 

         System.out.println(

             String.format(

                 "Should be found: %d. Found %d at index %d. An array length %d",

                 shouldBeFound, integers[atIndex], atIndex, size));

       }

}