数字格式 - Java

Question

我需要转换一个整数，以便在两个字符后插入破折号，例如12-34-56。

整数将是一个随机生成的六位数字。

Answer 1

int num = 123456;
String result = String.format("%02d-%02d-%02d",
    (num / 10000), (num%10000 / 100), (num%100));

Answer 2

    int num = 123456;
    char digits[] = Integer.toString(num).toCharArray();
    String what_you_want = "";
    for (int i = 0; i < digits.length; i += 2) {
        what_you_want += digits[i] + "" + digits[i + 1] + ((i < 4) ? "-" : "");
    }
    System.out.println(what_you_want);// output: 12-34-56