Making a user input only accept int but store in String

Question

Got my program done and this is the only piece I cant figure out I have to check to see if the user entered String userPhone is an integer

System.out.println("Please enter your phone number (10-dights only)");
        String userNumber=sc.nextLine();

        while(true) {
            if (userNumber.length()==10) {
                order01.cust1.setPhoneNumber(userNumber);
                break;
            }
            else if (userNumber.length()!=10) {
                System.out.println("Invalid phone number, Enter a valid one");
            }
            userNumber=sc.nextLine();
        }

You might want to take a look at https://stackoverflow.com/questions/123559/a-comprehensive-regex-for-phone-number-validation?noredirect=1&lq=1 in case you are specifically looking to match phone number patterns. — Naman, Oct 27 '17 at 04:05

score 0 · Answer 1 · answered Oct 27 '17 at 04:02

0

You could use a regular expression to validate that the String contains exactly ten digits that would be \d{10} - and you don't need an else after your break. Like,

while(true) {
     if (userNumber.matches("\\d{10}")) {
         order01.cust1.setPhoneNumber(userNumber);
         break;
     }
     System.out.println("Invalid phone number, Enter a valid one");
     userNumber=sc.nextLine();
}

answered Oct 27 '17 at 04:02

Elliott Frisch

198,278
20
158
249

but this solution only tests the length of userNumber it doesn't validate that the String contains only integers so it passes "abcdefghiJ" as a valid number – chris crosby Oct 27 '17 at 04:11
@chriscrosby No. `\\d{10}` will only match 10 digits. `0-9`. – Elliott Frisch Oct 27 '17 at 04:12
I was testing the wrong method this solution worked correctly – chris crosby Oct 27 '17 at 04:25

Devram Kandhare · Accepted Answer · 2017-10-27T15:51:09.647

0

check matching for digits. matches() method of string take regular expression. Here \d* represent all characters should be digits only. and before that we are checking for length also.

 while(true) {
        if (userNumber.length()==10 && userNumber.matches("\\d*")) {
            System.out.println(userNumber);
            break;
        }
        else if (userNumber.length()!=10 || !userNumber.matches("\\d*")) {
            System.out.println("Invalid phone number, Enter a valid one");
        }
        userNumber=sc.nextLine();
    }

edited Oct 27 '17 at 15:51

answered Oct 27 '17 at 04:08

Devram Kandhare

771
2
8
20

@chris use this one – Devram Kandhare Oct 27 '17 at 04:13
Is this useful for you? – Devram Kandhare Oct 27 '17 at 04:19

score 0 · Answer 3 · answered Oct 27 '17 at 04:11

0

The easiest and most primitive would be to loop through the input string(since your string is only 10 units long) and check if character at each index is a digit using Character.isDigit

answered Oct 27 '17 at 04:11

hsnsd

1,728
12
30

try using string methods which take regular expression . – Devram Kandhare Oct 27 '17 at 04:18

score 0 · Answer 4 · answered Oct 27 '17 at 04:13

0

Please refer for the link for more information and original credits to this link : Original Code

Try the below method:

       public static boolean isNumber(String string) {
        try {
            Long.parseLong(string);
        } catch (Exception e) {
            return false;
        }
        return true;
        }

in your code :

if (isNumber(userPhone)) {
         order01.cust1.setPhoneNumber(userNumber);
         break;
     }

answered Oct 27 '17 at 04:13

Karan

695
1
6
16

This also work fine but for validation it is more suitable to use regular expression. – Devram Kandhare Oct 27 '17 at 04:15
1

Yes it is better to use regular expression, I tried my best to answer !! – Karan Oct 27 '17 at 04:33

Making a user input only accept int but store in String

4 Answers4