Thread: "DO-OVER!" (5th grade kickball)

sorry about the stupid subject but I didnt know what else to use.

In my program I would like the input to be validated as a legitatime number and if its not then I want to see an error and ask to reinput the number.

Code:

Example:
Enter number 1: 
4
Integer Valid.

Enter number 2:
5f
Invalid Integer.  Please try again.

Enter nuber 2:
-8.8
Integer Valid.

So I really have 2 questions:
1) How can I get a loop to move back up to ask the question again (I hope that makes sense)
and
2) Can someone help me with the validation. It already accepts negative and decimals but I dont know how to get it to post an error if its invalid.

I know its not much, but here is what I have so far.

Code:

double Array[25];
for(int counter = 0; counter < maxnum ; counter++){
cout << "\nEnter number " <<(counter+1) << "\n";
cin >> Array[counter];  
cout << "\n";

i think you have to use a do while loop..

Originally posted by san
i think you have to use a do while loop..

What are you serious? You never HAVE to use a do while loop. I used to use them all of the time but now I hate them. You can use a simple while loop just fine.

Use a while loop.

syntax:

Code:

    while(condition is true)
    {
           //do what's in here 
    }

The condition can be any expression such as (i < 4) or ( i == 3 )

To do loop again if the user did something wrong, then use the
continue statement. This will jump back up to the beginning
of the loop.

You could also us a do...while() loop which will execute at least
once.

syntax:

Code:

   do
   {
        //do what's in here
   }while(condition is true);        //note the semi-colon

Here's an example:

Code:

   int i = 0;
   int array[6] = {1,2,3,4,5,-1};
   
   while( array[i] != -1)
   {
         cout << array[i] << " ";
   }

As for validation, you'd have to read the input into a string, then
test the characters of the string to see that the input was valid.

BUT
cin will accept anything so if the user enter a number then some
characters, then cin will ignore the charcters.

Sorry 'bout that code.
'i' isn't being incremented as it should be.

Code:

   int i = 0;
   int array[6] = {1,2,3,4,5,-1};
   
   while( array[i] != -1)
   {
         cout << array[i++] << " ";
   }

u could u do while if u want the loop to execute atleast once ..

pardon my ignorance if this is not correct tell me so that i can learn .. because i very new to c++ and this is my first reply for this post ..

Originally posted by san
u could u do while if u want the loop to execute atleast once ..

pardon my ignorance if this is not correct tell me so that i can learn .. because i very new to c++ and this is my first reply for this post ..

Well yes you could do it in a do while loop. If you re-read your post it sounds like you are saying the only way to do it is through a do while loop. Sorry for the confusion I just wanted to point out multiple options.