Question: I'm using to show exif data of a picture.

this is the code

```
<?php

  $filename = "http://www.rallyfun.net/images/20140921231511_img_7369.jpg";

  $exif = exif_read_data($filename, 0, true);

  echo "Exposure: " . $exif["EXIF"]["ExposureTime"] . " sec.<br />";
  echo "F: " . $exif["EXIF"]["FNumber"] . "<br />";
  echo "ISO: " . $exif["EXIF"]["ISOSpeedRatings"] . "<br />";

?>

```

this is the result:

```
Exposure: 1/6400 sec.
F: 63/10 sec.
ISO: 1000

```

the result is ok except for the aperture: it must be displayed as (in this case) 6.3 so i need to divide the first number (63) with the number after the "/" (10).

how?

Answer: 
Take help form the below snippet. This will help.

```
        List<String> l1 = new ArrayList<String>();
        List<String> l2 = new ArrayList<String>();

        l1.add("A");
        l1.add("B");
        l1.add("C");

        l2.add("C");
        l2.add("D");
        l2.add("E");

        Set<String> s = new HashSet<String>();
        s.addAll(l1);
        s.addAll(l2);

        List<String> finalList = new ArrayList<String>();
        finalList.addAll(s);

        for (String str : finalList) {
            System.out.println(str);
        }

```
Something like

```
Set<String> stringSet = new HashSet<>(Arrays.asList(new String[]{"1","2","3"}));
stringSet.addAll(Arrays.asList(new String[]{"1","2","3","4"}));
List<String> finalList = new ArrayList<>(stringSet);

```