# Overview

The methods **`toUpperCase`** and **`toLowerCase`** are used to convert strings to upper and lowercase respectively. The methods take a string and either convert all the letters to upper or lowercase. 

The following is the definition of `toUpperCase` in Scala:

```Scala
String toUpperCase()
```

The following is the definition of `toLowerCase` in Scala:

```Scala
String toLowerCase()
```

# Parameters

Both `toUpperCase` and `toLowerCase` do not take any input parameters. 

# Return value

`toUpperCase` returns a string in all uppercase letters, and `toLowerCase` returns a string in all lowercase letters.

# Example

The following is an example of how you can use the methods `toUpperCase` and `toLowerCase` to convert strings:



object Main extends App {
    val str = "Hello World!"
    val lowerstr = str.toLowerCase()
    val upperstr = str.toUpperCase()

    print("In lowercase: " + lowerstr + "\n")
    print("In uppercase: " + upperstr)
}

How to convert a string to lower and uppercase in Scala

Use `toUpperCase` and `toLowerCase` in Scala to convert strings to upper or lowercase, respectively.