You can combine filter expressions by using conditionals. This allows you to build powerful filtering logic.

## AND
  
`AND` is the conjunction operator.  
The following filter returns items which meet two conditions: the brand is `"abcd"` and the price is 10 or more.
```
brand == "abcd" AND price.value >= 10
```

## OR
  
`OR` is the alternative operator.  
The following filter returns items which meet at least one of the conditions:
- brand is `"abcd"`
- the price is 10 or more
```
brand == "abcd" OR price.value >= 10
```
If both conditions are met, the filter also matches the items (and/or logic).

## NOT

`NOT` is the negation operator.  
The following filter returns items whose brand is not `"abcd"`:
```
NOT(brand == "abcd")
```

## IF
If you want to add conditional logic to the filter, you can use the `IF` statement.

```
IF(predicate, thenFilter, elseFilter)
```
where:
- `predicate` is a logical expression in which you can use the context, but you cannot use properties of the item that is being tested against the filter.
- `thenFilter` - is returned if the predicate is true.
- `elseFilter` - is returned if the predicate is false.

### Examples

**Example 1**:  

A basic IF statement:

```
IF(context.brand == "abcd", brand == "abcd" , brand != "abcd")
```
- If the context item's brand is `"abcd"`, the resulting item filter is `brand == "abcd"` (items from the same brand as the context match the filter).
- Otherwise, the filter is `brand != "abcd"` (items from all other brands match the filter).

**Example 2**:  

IF statement with a reference to a segmentation and the [`ALL/NONE`](/developers/iql/functions#allnone) function:  
```
IF(client.segmentations HAS "39d39ad1-6d7b-4401-b067-998bf7d56d9f", price.value > 100, ALL)
```
If the context profile belongs to the `39d39ad1-6d7b-4401-b067-998bf7d56d9f` segmentation, the resulting item filter is `price.value > 100`. Otherwise, the filter matches all items in the database.

**Example 3**:  

IF statement nested in another IF statement:
```
IF("NewCustomer" IN client.tags, price.value > 100, IF(context.brand == "abcd", price.value <= 100, ALL))
```
- If the context profile's tags include `"NewCustomer"`, the item filter is `price.value > 100`. Otherwise, the nested IF statement is evaluated.
- In the nested IF statement, if the context item's brand is `abcd`, the filter is `price.value <= 100`. Otherwise, the filter matches all items in the database.

**Example 4**:  

IF statement with the `AND` logical operator in the predicate:  
```
IF("NewCustomer" IN client.tags AND context.brand == "abcd", price.value > 100, price.value <= 100)
```
If the context profile has the tag `NewCustomer` and the context item's brand is `abcd`, the filter matches items whose price is more than 100.

## Grouping expressions


The parentheses `()` allow you to group conditions in order to create more complex and nested expressions.  

**Example**:
```
(brand == "abcd" AND price.value >= 10) OR brand == "efgh"
```
The filter returns items which meet at least one of the following conditions:
- brand is `"abcd"` while the price is 10 or more (both conditions must be met).
- brand is `"efgh"`.