Why take up 21 bytes, on a 32-bit system, three pointers plus two numbers 5 * 4 = 20 (should be 20 bytes ah) Thank you for your answer!!!
https://redis.com/ebook/part-2-core-concepts/01chapter-9-reducing-memory-use/9-1-short-structures/9-1-1-the-ziplist-representation/ enter image description here
