#    
## Overview

The **`toLowerCase` method** converts all the characters in a string to lowercase and returns the converted string as a result. However, it doesn't change the actual string.

> Note: If the string is already in lowercase, then the string is returned as it is. 

## Syntax 

```dart
String toLowerCase()
```

## Argument 

This method doesn't take any arguments.

## Return value 

This method converts all the characters present in the current string to lowercase and returns it.

## Code 

The code given below shows us how to use the `toLowerCase` method:

void main() {
  // create a empty string
  var str = "TeST";
  
  print('The string is - $str.');
  // Convert the string to lowercase
  print("str.toLowerCase() : ${str.toLowerCase()}");

  str = "HeLLO";
  print('\nThe string is - $str.');
  // Convert the string to lowercase
  print("str.toLowerCase() : ${str.toLowerCase()}");
  
}

## Explanation

In the code above: 

* In line 3, we create a variable with the name `str` and assign a `"TeST"` string as a value.

* In line 7, we use the `toLowerCase` method to convert the `str` to a string with lowercase characters only. The `toLowerCase` method will return `test` as a result.

* In line 9, we change the value of the `str` variable to the `"HeLLO"` string.

* In line 12, we use the `toLowerCase` method to convert the `str` to a string with all lowercase characters. The `toLowerCase` method will return `hello` as a result.

What is the String.toLowerCase method in Dart?

Converts all characters in a string to lowercase, without altering the original string.