0x56794E 0x56794E - 1 month ago 6
Java Question

Why does this code using random strings print "hello world"?

The following print statement would print "hello world".
Could anyone explain this?

System.out.println(randomString(-229985452) + " " + randomString(-147909649));


And
randomString()
looks like this:

public static String randomString(int i)
{
Random ran = new Random(i);
StringBuilder sb = new StringBuilder();
while (true)
{
int k = ran.nextInt(27);
if (k == 0)
break;

sb.append((char)('`' + k));
}

return sb.toString();
}

Answer

When an instance of java.util.Random is constructed with a specific seed parameter (in this case -229985452 or -147909649), it follows the random number generation algorithm beginning with that seed value.

Every Random constructed with the same seed will generate the same pattern of numbers every time.