Linear Search in Array - Optimal Approach

Algorithm Steps

Given an array arr and a target key.
Iterate through the array from index 0 to n-1.
For each element, check if arr[i] == key.
If a match is found, return the index i.
If no match is found after the loop ends, return -1.

Linear Search in Array - Optimal Approach Code

Python

JavaScript

Java

C++

def linear_search(arr, key):
    for i in range(len(arr)):
        if arr[i] == key:
            return i
    return -1

# Sample Input
arr = [10, 20, 30, 40, 50]
key = 30
print("Element found at index:", linear_search(arr, key))

Detailed Step by Step Example

We are performing a linear search for the value 40 in the array.

{ "array": [10,20,30,40,50], "showIndices": true }

{ "array": ["key:", 40], "emptyIndices": [0], "highlightIndicesGreen": [1] }

Check index 0

Compare arr[0] = 10 with key = 40.

{ "array": [10,20,30,40,50], "showIndices": true, "highlightIndices": [0], "labels": {"0":"i"} }

No match. Continue to next index.

Check index 1

Compare arr[1] = 20 with key = 40.

{ "array": [10,20,30,40,50], "showIndices": true, "highlightIndices": [1], "labels": {"1":"i"} }

No match. Continue to next index.

Check index 2

Compare arr[2] = 30 with key = 40.

{ "array": [10,20,30,40,50], "showIndices": true, "highlightIndices": [2], "labels": {"2":"i"} }

No match. Continue to next index.

Check index 3

Compare arr[3] = 40 with key = 40.

Match found! Element 40 is equal to key 40. Return index 3.

{ "array": [10,20,30,40,50], "showIndices": true, "highlightIndicesGreen": [3], "labels": {"3":"i"} }

Linear Search in Array - Optimal Approach

Visualization

Algorithm Steps