Linear Search

The simplest search: walk the array front to back until the target appears. No preconditions — works on unsorted data — but every miss costs a full scan.

Category
Searching
Time complexity
O(n)
Space complexity
O(1)

Pseudocode

for i ← 0 to n−1
  if a[i] ≠ target: continue
  return i
return not found

Reference implementation

def linear_search(a, t):
    for i, v in enumerate(a):
        if v == t:
            return i
    return -1

Open the interactive Linear Search visualisation →