Clarification of const variable type declaration

I am another newbie trying to get a grip on programming the Arduino.

I have been reading through the examples and have run across a few things things that did not make sence to me.

I have been able to answer most questions by digging deper into the examples and reference library however I am not findind an answer to this:

In the Analog Sensor Calibration example, two variables are defined as constants:
(link not active since this is my first post. Annoying but very smart precaution on the part of the forum admins - 2 thumbs up there).
From the Arduino Home Page go to LEARNING then under the ANALOG I/O section

const int sensorMin = 1023; // minimum sensor value
const int sensorMax = 0; // maximum sensor value

Then in the setup() function they are reassigned values, multiple times in the first 5 seconds of execution.

// calibrate during the first five seconds
while (millis() < 5000) {
sensorValue = analogRead(sensorPin);

// record the maximum sensor value
if (sensorValue > sensorMax) {
sensorMax = sensorValue;
}

// record the minimum sensor value
if (sensorValue < sensorMin) {
sensorMin = sensorValue;
}
}

This I dont understand. I thought setting a variable as constant (const) was to keep a variables value from changing (ie not be variable )

Is there something special about changing constants in the setup() function or are constants not really unchangeable?

Thanks in advance for any clairification here. Also could you ppoint me to the resource that I could have looked through to have answered this for myself. I don’t mind asking questions…just hate to look dense.

const are not changeable - this should not compile.

[EDIT] it doesn't.

See, you're not dense! :D

Thanks AWOL! Learning something new is difficult enough. Add questioning yourself to that and..... :P

Next question is to whom do I report the inconsistancy with, so that it gets fixed before he next person trips over it.

I clicked on edit, but of course do not have edit privledges (no surprise there)

Next question is to whom do I report the inconsistancy with, so that it gets fixed before he next person trips over it.

I guess it goes in "Bugs and suggestions" (I'm new here too)