CODEWITHSUNDEEP
javastringinteger
Halid Balçıklı
Halid Balçıklı

Reputation: 23

only numeric numbers with control

Firstly I'm a new person here. I need to ask one question. 

Scanner klavye = new Scanner(System.in);

System.out.println("DDD-DD-DDDD enter bank number digit: ");
String hesapNo = klavye.nextLine();

if(hesapNo.length() != 11) {
   System.out.println("You need to enter number with 11 digit");
}
else {
   if(hesapNo.charAt(3) == '-' && hesapNo.charAt(6) == '-') {
       System.out.println(hesapNo + " is valid");
   }
   else {
      System.out.println(hesapNo + " is not valid");
   }
}

I want to take only digit number but If I write below like this: ABC-DC-SMND "The count is valid" how can I solve this problem?

Thanks for all of your interest.

Upvotes: 1

Views: 125

Answers (2)

Juan Carlos Mendoza
Juan Carlos Mendoza

Reputation: 5794

That can be done with a simple regex using String.matches:

Scanner klavye = new Scanner(System.in);

System.out.println("DDD-DD-DDDD enter bank number digit: ");
String hesapNo = klavye.nextLine();

if(hesapNo.matches("\\d{3}-\\d{2}-\\d{4}")){ // <-- this regex matches your pattern DDD-DD-DDDD
    System.out.println(hesapNo + " is valid");
}else{
    System.out.println("You need to enter number with 11 digit");
}

EDIT

If you want to keep asking for input until a valid one is entered then you can do this:

Scanner klavye = new Scanner(System.in);
String hesapNo;
boolean validInput;

System.out.println("DDD-DD-DDDD enter bank number digit: ");
do {
    hesapNo = klavye.nextLine();
    validInput = hesapNo.matches("\\d{3}-\\d{2}-\\d{4}");
    if (!validInput) { // if invalid input then warn the user
        System.out.println("Your bank number must be in DDD-DD-DDDD format");
    }
} while (!validInput); // loop until a valid input is provided
System.out.println(hesapNo + " is valid");

Upvotes: 1

Onur A.
Onur A.

Reputation: 3017

You can do it with regular expressions and a loop to prompt the user until a valid input.

Scanner klavye = new Scanner(System.in);

System.out.println("DDD-DD-DDDD enter bank number digit: ");
String hesapNo;
final String regexPattern = "\\d{3}-\\d{2}-\\d{4}";
do {
   hesapNo = klavye.nextLine();
   System.out.println("You need to enter a number with 11 digit with pattern: DDD-DD-DDDD");
}
while(!hesapNo.matches(regexPattern));

System.out.println(hesapNo + " is valid");

Upvotes: 2

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