What's wrong with this if statement?

[mnongkhlaw]

I want to detect if dates entered by users in a textbox contains JAN,FEB,MAR etc :

var goodDate = true;
var theChar = theInput.substring(2,5); //see theInput below
if (theChar != "JAN" || theChar != "FEB" || theChar != "MAR" || theChar != "APR" || theChar != "MAY" || theChar != "JUN" || theChar != "JUL" || theChar != "AUG" || theChar != "SEP" || theChar != "OCT" || theChar != "NOV" || theChar != "DEC"){

goodDate = false;
alert("theChar= "+theChar);
alert("goodDate= "+goodDate);
}

For example, when theInput="1/OCT/99" the first alertbox gives me theChar=OCT, but the second alertbox still gives me goodDate=false when I expect it to be true.

What's wrong with the above code?

Mark

 

[byam]

your origianl if statement mean: if theChar equal to any of Month, set goodDate = false. i.e. if a user enter a valid month set goodDate to false. Doesn't sound right!

Change logical OR to AND in the if statement.

// if theChar is not equal any of these
if (theChar != "JAN" && theChar != "FEB" && theChar != "MAR" && theChar != "APR" && theChar != "MAY" && theChar != "JUN" && theChar != "JUL" && theChar != "AUG" && theChar != "SEP" && theChar != "OCT" && theChar != "NOV" && theChar != "DEC&quot{

// then set goodDate to false as not matching any month.

or

no need to change the if statement, simply change default goodDate valueto false

var goodDate = false;

then inside if statement block, change

goodDate = true;

 

[mnongkhlaw]

byam,

I'm getting confused here : Doesn't != mean NOT equal to?

I changed || to && but I still get the same results!
&& doesn't sound right to me, anyway.

Mark

 

[mnongkhlaw]

byam,

I solved the problem by replacing != with == and setting goodDate=true

Mark