SADD

redis> SADD myset "Hello"
(integer) 1
redis> SADD myset "World"
(integer) 1
redis> SADD myset "World"
(integer) 0
redis> SMEMBERS myset
1) "Hello"
2) "World"

import redis

r = redis.Redis(decode_responses=True)

res1 = r.sadd("myset", "Hello", "World")
print(res1)  # >>> 2

res2 = r.sadd("myset", "World")
print(res2)  # >>> 0

res3 = r.smembers("myset")
print(res3)  # >>> {'Hello', 'World'}


res4 = r.sadd("myset", "Hello", "World")
print(res4)  # >>> 2

res5 = r.smembers("myset")
print(res5)  # >>> {'Hello', 'World'}

import static java.util.stream.Collectors.toList;

import java.util.Set;

import redis.clients.jedis.UnifiedJedis;

public class CmdsSetExample {

    public void run() {
        UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379");

        long sAddResult1 = jedis.sadd("myset", "Hello");
        System.out.println(sAddResult1); // >>> 1

        long sAddResult2 = jedis.sadd("myset", "World");
        System.out.println(sAddResult2); // >>> 1

        long sAddResult3 = jedis.sadd("myset", "World");
        System.out.println(sAddResult3); // >>> 0

        Set<String> sAddResult4 = jedis.smembers("myset");
        System.out.println(sAddResult4.stream().sorted().collect(toList()));
        // >>> [Hello, World]

        long sMembersResult1 = jedis.sadd("myset", "Hello", "World");
        System.out.println(sMembersResult1); // >>> 2

        Set<String> sMembersResult2 = jedis.smembers("myset");
        System.out.println(sMembersResult2.stream().sorted().collect(toList()));
        // >>> [Hello, World]

        jedis.close();
    }
}