Need Guidance for mobile number validation

Question

The Task it to check the input number is valid if it starts with only 7/8/9 and contains 10 digits. Here is the code. Correct me. I know I'm wrong.

public boolean validateMobileNumber(long number) throws Exception {

    String num = Long.toString(number);

    String regex = "@\"^[7-9]{10}$";
    if (num.equals(regex))
        return true;
    else
        throw new Exception("Invalid Number");
}

"7/8/9" may be misunderstood. If you mean "7", 8 or 9" you should say that. Also, please clarify if the digits at the beginning of the string can be followed by other characters. — Cary Swoveland, Apr 28 '20 at 19:54
Your regex will fail if *any* digit among the 10 is other than a `7`, `8` or `9`. Is that your intent? — Cary Swoveland, Apr 28 '20 at 19:58
no!! it should start with 7 or 8 or 9 and should contain 10 digits in total — karthik narayanan, Apr 28 '20 at 20:00
and also if I convert the Long number int String type and use it compare with regex, is that a correct way to validate. — karthik narayanan, Apr 28 '20 at 20:06
I don't know Java, but @SwissCodeMen's comment suggests you need to write `String regex = "@[7-9]\d{9}$";` — Cary Swoveland, Apr 28 '20 at 20:07

thibsc · Answer 1 · 2020-04-28T20:10:32.047

0

It's because you use equals to check the match of your regex. You will use matches

String num = "7123456789";
String regex = "^[7-9]\\d{9}$";

System.out.println(num.matches(regex));

edited Apr 28 '20 at 20:10

answered Apr 28 '20 at 20:06

thibsc

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Got it thibsc thanks mate – karthik narayanan Apr 28 '20 at 20:09

Need Guidance for mobile number validation

1 Answers1