---
title: "toUpperCase"
description: "Returns uppercase transformed String."
type: "function"
---

<div class='type'>Function</div>


<a id='references'></a>
<div class='sourceset sourceset-common'>Common</div>


```kotlin
fun String.toUpperCase(locale: Locale): String
```


Returns uppercase transformed String.

#### Parameters

| | |
| --- | --- |
| locale | a locale object |


#### Returns

| | |
| --- | --- |
|  | a transformed text |




<div class='sourceset sourceset-common'>Common</div>


```kotlin
fun String.toUpperCase(localeList: LocaleList): String
```


Returns uppercase transformed String.

#### Parameters

| | |
| --- | --- |
| localeList | a locale list object. If empty locale list object is passed, use current locale instead. |


#### Returns

| | |
| --- | --- |
|  | a transformed text |




<div class='sourceset sourceset-common'>Common</div>


```kotlin
fun AnnotatedString.toUpperCase(localeList: LocaleList = LocaleList.current): AnnotatedString
```


Create upper case transformed `AnnotatedString`

The uppercase sometimes maps different number of characters. This function adjusts the text style
and paragraph style ranges to transformed offset.

Note, if the style's offset is middle of the uppercase mapping context, this function won't
transform the character, e.g. style starts from between base alphabet character and accent
character.

#### Parameters

| | |
| --- | --- |
| localeList | A locale list used for upper case mapping. Only the first locale is effective. If empty locale list is passed, use the current locale instead. |


#### Returns

| | |
| --- | --- |
|  | A uppercase transformed string. |