Java linear search

Author: sarthak-trivedi

data-structures/LinearSearch.java

@@ -0,0 +1,45 @@
+/*
+    Program to find a particular key in the array (Linear-search)
+*/
+
+import java.util.Scanner;
+
+class LinearSearch{
+    public static void main(String args[]){
+        Scanner sc = new Scanner(System.in);
+        System.out.println("How many elements the array have?");
+        System.out.print("Answer : ");
+        try{
+            int[] arr = new int[sc.nextInt()];
+            System.out.println("Enter elements one by one");
+            for(int i = 0 ; i < arr.length; i++){
+                System.out.print("Enter arr["+i+"] : ");
+                arr[i] = sc.nextInt();
+            }
+            System.out.print("Enter the key you want to find : ");
+            int index = searchForKey(arr, sc.nextInt());
+            if(index == -1){
+                System.out.println("Sorry! Key is not in the array");
+            }else{
+                System.out.println("Key found on index -> "+index);
+            }
+        }catch(Exception e){
+            System.out.println(e);
+        }
+    }
+
+    public static int searchForKey(int[] arr, int key){
+        /*
+            This function looks for the key in the array and returns index when key found and -1 if key is not in the array.
+        */
+        for(int i=0; i < arr.length; i++){
+            // Searching elements one by one
+            if(arr[i] == key){
+                //returns index if found
+                return i;
+            }
+        }
+        //if failed to find key return -1
+        return -1;
+    }
+}