# What Is Linear Search Algorithm in Data Structure?

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Heather Bennett

Linear search is a simple yet fundamental algorithm used in data structures to search for a particular element in a collection of data. It is also known as sequential search since it checks each element sequentially until a match is found. This algorithm is commonly used when the data collection is not sorted or when the size of the collection is small.

## How Does Linear Search Work?

The linear search algorithm starts by comparing the Target element with the first element in the collection. If they match, the search ends successfully. If not, it moves on to compare the Target element with the second element, and so on, until either a match is found or all elements have been checked.

### Implementing Linear Search in Code

To implement linear search in code, you can use any programming language that supports loops. Here’s an example using Python:

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

In this example, arr represents the collection of elements to be searched, and target represents the element we are looking for. The function iterates over each element in arr and compares it with target.

If a match is found, the index of that element is returned. If no match is found after checking all elements, -1 is returned.

## Analyzing Linear Search Performance

The time complexity of linear search can be expressed as O(n), where n represents the number of elements in the collection being searched. This means that as the size of the collection increases, the time taken by linear search also increases linearly.

In terms of space complexity, linear search has a constant space complexity of O(1) since it does not require any additional data structures to perform the search.

## When to Use Linear Search?

Linear search is best suited for small collections or when the collection is not sorted. It is a simple and intuitive algorithm that can be easily implemented in any programming language. However, its performance may become inefficient for large collections, as it needs to check each element one by one.

It is important to note that if you have a sorted collection, other search algorithms such as binary search could provide better performance with their logarithmic time complexity.

## Conclusion

Linear search is a basic algorithm used to find an element in a collection of data. It works by sequentially comparing each element until a match is found or all elements have been checked.

Although it has a linear time complexity, making it less efficient for large collections, linear search remains useful in situations where the collection is small or unsorted. By understanding this fundamental algorithm, you can apply it to your own projects and gain a deeper understanding of data structures.