This book is a collection of notes and sample codes written by the author while he was learning sorting algorithms. Topics include introduction of sorting algorithms: Bubble Sort, Heap Sort, Insertion Sort, Merge Sort, Quicksort, Selection Sort, Shell Sort; Sorting algorithm implementations in Java, PHP, Perl and Python; Sorting algorithm performance comparison. Updated in 2024 (Version v6.12) with minor changes. For latest updates and free sample chapters, visit https://www.herongyang.com/Sort.