This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::Logs::Transformer LowerCaseString
<a name="aws-properties-logs-transformer-lowercasestring"></a>

This processor converts a string to lowercase.

For more information about this processor including examples, see [ lowerCaseString](https://docs.amazonaws.cn/AmazonCloudWatch/latest/logs/CloudWatch-Logs-Transformation-Processors.html#CloudWatch-Logs-Transformation-lowerCaseString) in the *CloudWatch Logs User Guide*.

## Syntax
<a name="aws-properties-logs-transformer-lowercasestring-syntax"></a>

To declare this entity in your Amazon CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-logs-transformer-lowercasestring-syntax.json"></a>

```
{
  "[WithKeys](#cfn-logs-transformer-lowercasestring-withkeys)" : [ String, ... ]
}
```

### YAML
<a name="aws-properties-logs-transformer-lowercasestring-syntax.yaml"></a>

```
  [WithKeys](#cfn-logs-transformer-lowercasestring-withkeys): 
    - String
```

## Properties
<a name="aws-properties-logs-transformer-lowercasestring-properties"></a>

`WithKeys`  <a name="cfn-logs-transformer-lowercasestring-withkeys"></a>
The array caontaining the keys of the fields to convert to lowercase.  
*Required*: Yes  
*Type*: Array of String  
*Minimum*: `1`  
*Maximum*: `10`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)