5
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I want to make sure if it's good. Maybe there is another better solution.

List<String[]> list = new ArrayList<String[]>();
    for (int i = 0; i < 3; i++) {
        String[] arr = { String.valueOf(i) };
        list.add(arr);
    }

    String json = new Gson().toJson(list);
    System.out.println(json);

Expected output:

[
[
"0"
],
[
"1"
],
[
"2"
]
]
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  • \$\begingroup\$ Please give a brief explanation of the purpose of the code in the question. Even quoting verbatim is ok (if the licence allows it) \$\endgroup\$ – Caridorc Dec 14 '15 at 18:48
4
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If you are able to use Java 8 you can use streams:

List<String[]> list = IntStream.range(0, 3)
    .mapToObj(i -> new String[] { String.valueOf(i) })
    .collect(Collectors.toList());

Let's break it down:

  • IntStream.range(0, 3) gives you the values 0, 1 and 2
  • .mapToObj(i -> new String[] { String.valueOf(i) }) converts them to a string and puts them into a String[]
  • .collect(Collectors.toList()) collects the stream into a List<String[]>
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  • \$\begingroup\$ +1, but unfortunately I can't use java 8 \$\endgroup\$ – Adamo Dec 14 '15 at 18:16

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