Linear vs Binary Search — Sorting and Searching Algorithms | IGCSE Computer Science

Exam Frequency Analysis

Past paper frequency (2018 to 2024)

This topic accounts for approximately 7% of your exam marks.

stable

Low

Stable7%

Bubble sort traces and binary search descriptions appear in nearly every paper. 4 to 6 marks.

A side-by-side comparison is a frequent exam question.

Feature	Linear search	Binary search
Does the list have to be sorted?	No	Yes
How it works	Checks every item in order, one at a time	Halves the search range each step
Speed on small lists	Roughly the same	Roughly the same
Speed on large lists	Slow (up to n comparisons)	Fast (up to log₂ n comparisons)
Simplicity	Very simple to write and understand	More complex; needs care with indices
Memory required	Minimal	Minimal
Best for	Short or unsorted lists; one-off searches	Long, sorted lists; repeated searches

If your data is already sorted and large, use binary search.
If your data is unsorted and you only need to search once, use linear search (sorting first would be slower than just looking).
If your data is unsorted but you will search many times, sort once and then use binary search for each query.