const Redis = require("ioredis"); const redis = new Redis(); async function main() { const numbers = [1, 3, 5, 7, 9]; await redis.sadd("user-set", numbers); const elementCount = await redis.scard("user-set"); console.log(elementCount); // 5 await redis.sadd("user-set", "1"); const newElementCount = await redis.scard("user-set"); console.log(newElementCount); // 5 const isMember = await redis.sismember("user-set", 3); console.log(isMember); // 1 (means true, and if it's 0, it means false) } main();