1. Function declaration
Receive an array and the value we want to find.
function linearSearch(arr, target)Typorithm · easy
Linear Search
▷ Interactive algorithm labsearchlinear-searchscanlinear-time
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Full lesson · 8 learning steps Open any exercise for focused practice
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Step 1 of 8 · intro card
Learn Linear Search
Search Algorithms
Linear Search scans values one by one until it finds the target.
Linear Search is the simplest way to find a value in an array.
It checks each item from left to right and stops as soon as the target is found.
If the target never appears, the function returns -1.
Preparing algorithm lab…
01
Scan from index 0 to the end.
02
Compare each value with target.
03
Return the matching index.
04
Worst-case time is O(n).
function linearSearch(arr, target) {
for (let i = 0; i < arr.length; i++) {
if (arr[i] === target) {
return i;
}
}
return -1;
}Read the implementation
Connect each part of the code to the concept before you type.
2. Scan loop
Check each index from left to right until the target is found.
for (let i = 0; i < arr.length; i++)3. Target check
Compare the current value with the target using strict equality.
arr[i] === target4. Return index
Return the index where the target was found.
return i5. Not found
Return -1 after the loop if the target never appears.
return -1A complete learning loop
01
Understand
Read the concept map and follow the code breakdown.
02
Reconstruct
Type the implementation, repair mistakes and work through every recall exercise.
03
Verify
Use the final check without hints; revisit weak concepts in short practice sessions.