Help me with my project.

Question

1.00/5 (1 vote)

See more:

Hello, I am working in our project in school. Our project is about ATM.

I first put asterisk while inputing the user's PIN, just like in ATM.

but since it is a char I can't compare it to numbers like

if (pin >= 0) ... it won't work. Can you help me?

What I have tried:

char pin[4];
string pass = "afgt";
int p;
int i=1;

cout << "ENTER PIN\t::\t";
if ((pin >= 0) && (pin <= 9)){
for (i=1;i<=4;i++){
pin[i]=getch();
cout << "*";
}
}

this one....

Posted 29-Oct-18 21:23pm

Member 14037488

Updated 29-Oct-18 21:56pm

Add a Solution

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Nelek · Answer 1 · 2018-10-29T21:33:00

you should learn to use the debugger. That will help you learn by finding your own errors.

As it is, you are saving the user's input in the variable within the IF snippet.
So, if the variable has not been saved yet, how is the if ((pin >= 0) && (pin <= 9)) statement going to match?

Secondly, what happens if the user inputs something wrong (e.g. a letter)? As it is, the program would end without giving any reason.

I recommend you to think what you want to achieve, put it in paper and then try to translate it into code. That should make it a bit easier for you to order your ideas.

Richard MacCutchan · Answer 2 · 2018-10-29T21:57:00

Solution 3

C++

if ((pin >= 0) && (pin <= 9)){

You have declared pin as an array of 4 characters so you can not compare it to a number. You should check each character in turn like:

C++

pin[i] = getch();
if (pin[i] < ‘0’ || pin[i] > ‘9’)
{
    // error message here
}

Posted 29-Oct-18 21:57pm

Richard MacCutchan

Comments

CPallini 30-Oct-18 4:18am

But if you don't allow the user to enter alphabetic characters, how could he possibly match the password?
:-)

Richard MacCutchan 30-Oct-18 11:15am

If the password is letters and the pin is numbers, the criminals will never get it.

CPallini 30-Oct-18 12:08pm

Brilliant! :thumbsup:

CPallini · Answer 3 · 2018-10-29T21:55:00

As matter of fact, the

Quote:
f ((pin >= 0) && (pin <= 9))

is plain wrong (other than useless).
It looks you're allowed to use C++ strings. If you are also allowed to use modern C++ features then try:

C++

#include <iostream>
#include <array>
using namespace std;


int main()
{
  using Code = array<char, 4>;

  const Code pwd{'a','f','g','t'};
  Code pin;
    
  cout << "please enter the pin\n";
  for (auto & c : pin)
    cin >> c;
  
  if ( pwd == pin)
    cout << "that's OK\n";
  else
    cout << "sorry, no luck\n";
}

Help me with my project.

3 solutions

Solution 1

Solution 3

Solution 2

Add your solution here

Preview 0