What Is Linear Search?

Linear Search is searching from the first element till you find the element that you are looking for. If no value is found return -1 For Example arr = [2,5,10,15,-19,35,8,-6,17] and the target element is 35 which is present in the 5th index. So you need to check the first index i.e. arr[0] and compare it with the target element, if it matches it will return the index value of the target element. If not found go for the second index i.e. arr[1] and so on till you find which index number matches the target element.

Time Complexity Of Linear Search

Best case : 0(1) It's when we start looking for the target element and find it in the first index, eliminating the need to look at other components. Let's say you have a 1 lakh-element array, and the target element is in the first index, which means it will only have to make one comparison.

Worst case : 0(N) N = Size of array In the worst-case scenario, it will continue to examine all of the elements in the specified array until the target element is found. Now, let's take the same array with 1 lakh items, and if the target element isn't discovered, It will have to perform 1 lakh comparisons.

Code For Linear Search

public class Main { public static void main(String[] args) { int[] nums = {23, 45, 1, 2, 8, 19, -3, 16, -11, 28}; int target = 19; boolean ans = linearSearch(nums, target); System.out.println(ans); }

  // search the target 
  static int linearSearch(int[] arr, int target) 
  {
         if (arr.length == 0)
         {
               return -1;
         }

        // run a for loop
        for (int index = 0 ; index<arr.length ; index++ ){
        //check for element at every index if it is equals to target element
        int element = arr[index]
        if (element == arr[index])
        {
              return index;
        }
   }
   // this line will execute if none of the return statements above has executed
   // hence the target was not found
   return -1;

}