compare 8 date fields

If you want to avoid using the nested loop, use the following algo for checking redundancy.

1)  Initialize a String variable varDateString, with the first date value (say 10/25/2009)
2)  Take the other date values one by one and do the following with each date value
   a)  check if this date is already a substring of varDateString (variable initialized above)
   b)  If yes, then there is a redundancy, exit out of the loop.
   c)  If no, then continue untill the loop is over or the redundancy is found

Let me know if this was helpful

Thanks

After step 2c), don't forget to concatenate the new date value in varDateString (variable initialized in 1)

gurvinder372: How is your "pseudo-solution" better than my real solution? What is the problem with a "nested loop" that it should be avoided?

Besides, you use the word "loop" in your "solution", so there is a loop regardless.

I don't get it.

Dear Badotz,

1) This is an alternate solution and it is upon the author of this question to accept it or not.
2) I have mentioned explicitly, that author can use this solution if he wants to avoid the nested loops.
3) I haven't mentioned that this is a better solution

Besides,
1) We are discouraged to give the source code as answer to a question.
2) With a nested loop, the complexity of the program becomes n2 (n square), with n is the number of times loop runs. But with a single loop, the complexity is n (or linear). So there is a case to avoid nested loops, as they are slower than the linear design.

Let me know if it helped.

1. It is not a solution
2. It is not a solution
3. You imply it is by your terminology

Besides
1. Sheer nonsense
2. Where is there a "nested loop"?

Badotz: -
Your code, does it ignore if the text field was blank, because if its blank, that text box can be ignored completely, only do compare for duplication if there is a date value in the field.

It should. Why don't you try it and see?

blank fields cause issues

Try this:

var val = [],
    chk = ''; 
function dates_ok() {
    for (var i = 1; i < 9; i += 1) {
        dat = document.getElementById('txtDate' + i).value;
        if (chk != '' && chk.indexOf(dat) >= 0)
            return false; // Found a matching date
        }
        chk += dat;
    }
    return true; // No matching dates
}

                                              

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Something still not working right...this is what I have filled in below....
Below is my code, with some alerts.
            status = "valid";
            for (var i = 1; i < 9; i += 1)
            {
                dat = document.getElementById('txtSession' + i).value;
                 if (chk != '' && chk.indexOf(dat) >= 0)
                {
                    alert(chk.indexOf(dat));
                    alert("There is a duplicate date in Session " + i);
                    status = "invalid";
                    return false; // Found a matching date
                }
                chk += dat;
            }
            return true; // No matching dates

When I run the code this is the alert I get
First alert is 0
Second alert is  There is a duplicate date in Session 3

txtDate1 = 11/16/2009
txtDate2 = 11/17/2009
txtDate3 =
txtDate4 =
txtDate5 =
txtDate6 =
txtDate7 =
txtDate8 =

Add this right after the "dat =" statement:

alert('->' + dat + '<');

That should display "-><-" If it does not, then change:

chk += dat;

to

if (dat != 'VALUE_FROM_THE_ALERT_GOES HERE') { chk += dat; }

your alert displayed the blank like you expected "-><-"
but what is weird, after all the alerts, I pressed submit again (without changing any dates) and here are my alerts.
->11/16/2009<
There is a duplicate date in Session 1

so something weird is going on...

>>so something weird is going on...

Not at all. "chk" is not being cleared.

Move the var declarations inside the function:

function dates_ok() {
    var val = [],
        chk = '';

The strong, silent type, eh?

No worries - glad to help.

Sorry, I thought the accept and all scores says it all...

thanks again.