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Strings

 
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Strings, Boolean Statement Problems
grinsalot
19 Sep, 2006 - 10:45 AM
Post #1

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Hi,

I'm having some problems with my boolean statement. I need the bool to return false if the user does not enter only the letters A or C. However, this bool always returns false. I can't seem to figure out why.

Thank you in advance for any suggestions or help.


CODE
int main()
{
  cin >> string_1;
  for(int i=0;i<string_1.length();i++)
      if(string_1[i] != 'A' || 'C')
        {
          cout << "Try again." << endl;
          cin >> string_1;
        }
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Nova Dragoon
RE: Strings
19 Sep, 2006 - 10:56 AM
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part of the problem is this line:
if(string_1[i] != 'A' || 'C')

which needs to look like:
if(string_1[i] != 'A' || string_1[i] != 'C')
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grinsalot
RE: Strings
19 Sep, 2006 - 11:11 AM
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Thank you for your help Nova Dragoon. I'm still not able to get the program to run properly though. My bool statement always evaluates to false on the first run-through.
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Nova Dragoon
RE: Strings
19 Sep, 2006 - 11:17 AM
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edit: I read the quesiton wrong
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Xing
RE: Strings
19 Sep, 2006 - 11:32 AM
Post #5

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User is entering a string or a single character?
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grinsalot
RE: Strings
19 Sep, 2006 - 11:54 AM
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Hi Xing,

The user is entering a string of as many letters as they like. However, the string can only contain A and C. If the string contains any other letters, I have to identify the incorrect entries.

Thank you.

I have worked out some alternate code. It too is failing, however.

CODE
int main()

{
   int i = 0;
   cin >> string_1;
   int length = string_1.length();
     while(i<length){
                 while(string_1[i] !='A' || string[i] != 'C')
      {
           cout << "Try again." << endl;
           cin >> string_1;
            i = i + 1;
      }
  }


This post has been edited by grinsalot: 19 Sep, 2006 - 12:04 PM
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Xing
RE: Strings
19 Sep, 2006 - 12:23 PM
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Replace || with &&

This post has been edited by Xing: 19 Sep, 2006 - 12:23 PM
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Amadeus
RE: Strings
19 Sep, 2006 - 12:26 PM
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You'll likely want to check for the AND condition...not the OR.

[edit]Xing beat me too it! smile.gif[/edit]
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grinsalot
RE: Strings
19 Sep, 2006 - 12:30 PM
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QUOTE(Xing @ 19 Sep, 2006 - 01:23 PM) *

Replace || with &&

Thank you Xing and Amadeus! It's the details that I consistently seem to miss. Note to self: Pay attention!

Thank you, again.
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violent_crimson
RE: Strings
19 Sep, 2006 - 03:41 PM
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#include <iostream>
using namespace std;

char szInput [3];

int main () {
//get one character from the user into the array

if (szInput [1] != 'a' && szInput [1] != 'c') {
//you entered an invalid character..
}
return 0;
}
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Amadeus
RE: Strings
19 Sep, 2006 - 05:27 PM
Post #11

g++ -o drink whiskey.cpp
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His code was working with the small change that was suggested.
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Xing
RE: Strings
19 Sep, 2006 - 05:36 PM
Post #12

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@violent_crimson
Code Tags Please
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