# Empty test

Learn how to check if a value is empty.

This test checks whether a value is empty.

An operand is considered empty if it is null, an empty string, or a collection with no elements. Anything else is considered not empty.

## Syntax

This test has the following syntax:

```cql
/*<value>*/ is empty
```

To negate the test, use the following syntax:

```cql
/*<value>*/ is not empty
```

## Parameters

These are the supported parameters:

- `value`: `any`

  The value to validate.

## Examples

Here is an example of how to check if a string is empty:

```cql
"Hello, world!" is empty // false
```

And this is how you can check if a collection is empty:

```cql
[] is empty // true
```