# ZADD

> Add a member to a sorted set, or update its score if it already exists.

## Arguments 

<ParamField body="key" type="string" required>
  The key of the sorted set.
</ParamField>

<ParamField body="options">
    <ParamField body="xx" type="boolean">
        Only update elements that already exist. Never add elements.
    </ParamField>
    <ParamField body="nx" type="boolean">
        Only add new elements. Never update elements.
    </ParamField>
    <ParamField body="ch" type="boolean">
        Return the number of elements added or updated.
    </ParamField>
    <ParamField body="incr" type="boolean">
        When this option is specified ZADD acts like ZINCRBY. Only one score-element pair can be specified in this mode.
    </ParamField>
    <ParamField body="gt" type="boolean">
        Only update existing elements if the new score is greater than the current score. Add element without a check if it does not exist.
    </ParamField>
    <ParamField body="lt" type="boolean">
        Only update existing elements if the new score is less than the current score. Add element without a check if it does not exist.
    </ParamField>
</ParamField>

## Response

<ResponseField type="integer"  required>
    The number of elements added to the sorted sets, not including elements already existing for which the score was updated.

    If `ch` was specified, the number of elements that were updated.

    If `incr` was specified, the new score of `member`.
</ResponseField>



<RequestExample>
```ts Simple
await redis.zadd(
    "key", 
    { score: 2, member: "member" }, 
    { score: 3, member: "member2"},
);
```

```ts XX 
await redis.zadd(
    "key",
    { xx: true },
    { score: 2, member: "member" },
)
```

```ts NX 
await redis.zadd(
    "key",
    { nx: true },
    { score: 2, member: "member" },
)
```

```ts CH 
await redis.zadd(
    "key",
    { ch: true },
    { score: 2, member: "member" },
)
```

```ts INCR 
await redis.zadd(
    "key",
    { cincrh: true },
    { score: 2, member: "member" },
)
```

```ts GT
await redis.zadd(
    "key",
    { gt: true },
    { score: 2, member: "member" },
)
```

```ts LT
await redis.zadd(
    "key",
    { lt: true },
    { score: 2, member: "member" },
)
```
</RequestExample>