Arrays

Part of Insertion Sort · Section 3 of 8

Study NotesUnit: 3.1 Fundamentals of AlgorithmsGCSE

This study notes covers Arrays within Insertion Sort for GCSE Computer Science. Revise Insertion Sort in 3.1 Fundamentals of Algorithms for GCSE Computer Science with 15 exam-style questions and 10 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 8 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.

Arrays

Operation GCSE Pseudocode Example
Declare 1D array array name[size] array scores[10]
Access element name[index] scores[0] = 85
Declare 2D array array name[rows, cols] array grid[3, 4]
Access 2D name[row, col] grid[1, 2] = "X"

Note: Arrays are 0-indexed (first element is index 0)

Practice questions for Insertion Sort

Which statement best describes how insertion sort works?

  • A. It repeatedly swaps adjacent elements until the list is sorted
  • B. It divides the list in half repeatedly and merges sorted halves
  • C. It takes each element and inserts it into its correct position in the already sorted portion
  • D. It selects the smallest element and swaps it to the front each pass
1 markfoundation

Describe how insertion sort works. Your answer should include how the algorithm processes each element.

3 marksstandard

Quick recall flashcards

How does insertion sort work?
Builds sorted list one element at a time by inserting each element into its correct position
What is the time complexity of insertion sort?
O(n²) worst/average case, O(n) best case (already sorted)

Previous

Organising Data

Next

Deep Dive: 2D Arrays

15 questions on Insertion Sort — practise free

Instant marking, adaptive difficulty and spaced-repetition flashcards — all aligned to your exam board.

Start revising free →