---
title: "lowercased(with:)"
framework: foundation
role: symbol
role_heading: Instance Method
path: "foundation/nsstring/lowercased(with:)"
---

# lowercased(with:)

Returns a version of the string with all letters converted to lowercase, taking into account the specified locale.

## Declaration

```swift
func lowercased(with locale: Locale?) -> String
```

## Parameters

- `locale`: The locale. For strings presented to users, pass the current locale ([doc://com.apple.foundation/documentation/Foundation/NSLocale doc://com.apple.foundation/documentation/Foundation/NSLocale/current]). To use the system locale, pass nil.

## Return Value

Return Value A lowercase string using the locale.

## Discussion

Discussion Case transformations aren’t guaranteed to be symmetrical or to produce strings of the same lengths as the originals. See lowercased for an example.

## See Also

### Changing Case

- [lowercased](foundation/nsstring/lowercased.md)
- [localizedLowercase](foundation/nsstring/localizedlowercase.md)
- [uppercased](foundation/nsstring/uppercased.md)
- [localizedUppercase](foundation/nsstring/localizeduppercase.md)
- [uppercased(with:)](foundation/nsstring/uppercased(with:).md)
- [capitalized](foundation/nsstring/capitalized.md)
- [localizedCapitalized](foundation/nsstring/localizedcapitalized.md)
- [capitalized(with:)](foundation/nsstring/capitalized(with:).md)