Is there a way to create a loop which while only stop if specific strings are entered?

Question

What I'm trying to do is make a loop which prompts the user for information and will only stop if certain strings are entered. Specifically, I want it only to accept certain letters, both upper and lowercase. Here's what I have so far:

 do
 {
  salesP = prompt("Enter the initial of the first name of the salesperson: ", "");
 }while (salesP != "C" || salesP != "c")

Basically the while part is completely wrong and I know it. I've tried everything I can think of, and the best I can do is get it to accept a single variable. I also need it to accept d, x, and m, both cases.

Answer 1

Option 1 Permanent loop with an if statement, can use multiple if statements or other control structures to check for when to break.

while 1:
   if(raw_input('Enter some data please:') == specialString):
      break

Option 2 Part of loop

tempstring = ""
while (tempstring != specialString):
    tempstring = raw_input('Enter some data please:')

Option 3: Recursion

def dataEntry(a,b,c):
    #data validation statements that fail on first iteration
    #statements to prompt user about data
    dataentry(a,b,c)

As far as how to check for the right string, I would recommend regular expressions. Googling for "regex" examples is much better than me trying to explain it.

Answer 2

That code is almost correct. You simply use the incorrect boolean operator in your while statement. You're using OR (||) where you should use AND (&&).

So:

 do
 {
  salesP = prompt("Enter the initial of the first name of the salesperson: ", "");
 }while (salesP != "C" && salesP != "c")

Answer 3

Something else to play with that if you are new you should become REALLY familiar with when doing string comparison is to eliminate case from the equation completely:

do
 {
  salesP = prompt("Enter the initial of the first name of the salesperson: ", "");
 }while (salesP.toLowerCase() != 'c')

Answer 4

just another approach

function promptSalesP(){
var _salesP = prompt("Enter the initial of the first name of the salesperson: ", "");
if(_salesP.toLowerCase() == "c")
return _salesP;
else
return promptSalesP(); 
}

var salesP = promptSalesP();