public/subjects/java/piscine/StreamMap/README.md

## StreamMap

### Instructions

Create a file `StreamMap.java`.

Create a function `sumOfStringLength` which returns the sum of the length of the strings in the stream.  
Create a function `upperCaseAllString` which returns the list of all the strings in upper case.  
Create a function `uniqIntValuesGreaterThan42` which keeps only doubles greater than 42, transforms the doubles to integers and returns them as a set.


### Expected Functions
```java
public class StreamMap {
    public static Integer sumOfStringLength(Stream<String> s) {
        // your code here
    }

    public static List<String> upperCaseAllString(Stream<String> s) {
        // your code here
    }
    
    public static Set<Integer> uniqIntValuesGreaterThan42(Stream<Double> s) {
        // your code here
    }
}
```

### Usage

Here is a possible ExerciseRunner.java to test your function :

```java
import java.io.IOException;
import java.util.stream.Stream;

public class ExerciseRunner {
    public static void main(String[] args) throws IOException {
        System.out.println(StreamMap.sumOfStringLength(Stream.of("Bonjour", "le", "monde !")));
        System.out.println(StreamMap.upperCaseAllString(Stream.of("IL", "Fait", "beaU !!")));
        System.out.println(StreamMap.uniqIntValuesGreaterThan42(Stream.of(23.439, 42.34, 39194.4)));
    }
}
```
          
and its output :
```shell
$ javac *.java -d build
$ java -cp build ExerciseRunner 
16
[IL, FAIT, BEAU !!]
[42, 39194]
$ 
```

### Notions
[Stream](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/stream/Stream.html)