Middle three digits: Difference between revisions

=={{header|Java}}==

<lang d>public class MiddleThreeDigits {

public static void main(String[] args) {

final long[] passing = {123, 12345, 1234567, 987654321, 10001, -10001,

-123, -100, 100, -12345, Long.MIN_VALUE, Long.MAX_VALUE};

final int[] failing = {1, 2, -1, -10, 2002, -2002, 0, Integer.MIN_VALUE,

Integer.MAX_VALUE};

for (long n : passing)

System.out.printf("middleThreeDigits(%s): %s\n", n, middleThreeDigits(n));

for (int n : failing)

System.out.printf("middleThreeDigits(%s): %s\n", n, middleThreeDigits(n));

}

public static <T> String middleThreeDigits(T n) {

String s = String.valueOf(n);

if (s.charAt(0) == '-')

s = s.substring(1);

int len = s.length();

if (len < 3 || len % 2 == 0)

return "Need odd and >= 3 digits";

int mid = len / 2;

return s.substring(mid - 1, mid + 2);

}

}</lang>

<pre>middleThreeDigits(123): 123

middleThreeDigits(12345): 234

middleThreeDigits(1234567): 345

middleThreeDigits(987654321): 654

middleThreeDigits(10001): 000

middleThreeDigits(-10001): 000

middleThreeDigits(-123): 123

middleThreeDigits(-100): 100

middleThreeDigits(100): 100

middleThreeDigits(-12345): 234

middleThreeDigits(-9223372036854775808): 368

middleThreeDigits(9223372036854775807): 368

middleThreeDigits(1): Need odd and >= 3 digits

middleThreeDigits(2): Need odd and >= 3 digits

middleThreeDigits(-1): Need odd and >= 3 digits

middleThreeDigits(-10): Need odd and >= 3 digits

middleThreeDigits(2002): Need odd and >= 3 digits

middleThreeDigits(-2002): Need odd and >= 3 digits

middleThreeDigits(0): Need odd and >= 3 digits

middleThreeDigits(-2147483648): Need odd and >= 3 digits

middleThreeDigits(2147483647): Need odd and >= 3 digits</pre>