Phone number validation Android

Question

How do I check if a phone number is valid or not? It is up to length 13 (including character + in front).

How do I do that?

I tried this:

String regexStr = "^[0-9]$";  String number=entered_number.getText().toString();    if(entered_number.getText().toString().length()<10 || number.length()>13 || number.matches(regexStr)==false  ) {     Toast.makeText(MyDialog.this,"Please enter "+"\n"+" valid phone number",Toast.LENGTH_SHORT).show();     // am_checked=0; }` 

And I also tried this:

public boolean isValidPhoneNumber(String number) {      for (char c : number.toCharArray())      {          if (!VALID_CHARS.contains(c))          {             return false;          }      }      // All characters were valid      return true; } 

Both are not working.

Input type: + sign to be accepted and from 0-9 numbers and length b/w 10-13 and should not accept other characters

Answer 1

Use isGlobalPhoneNumber() method of PhoneNumberUtils to detect whether a number is valid phone number or not.

Example

System.out.println("....g1..."+PhoneNumberUtils.isGlobalPhoneNumber("+912012185234")); System.out.println("....g2..."+PhoneNumberUtils.isGlobalPhoneNumber("120121852f4")); 

The result of first print statement is true while the result of second is false because the second phone number contains f.

Answer 2

Given the rules you specified:

upto length 13 and including character + infront.

(and also incorporating the min length of 10 in your code)

You're going to want a regex that looks like this:

^\+[0-9]{10,13}$ 

With the min and max lengths encoded in the regex, you can drop those conditions from your if() block.

Off topic: I'd suggest that a range of 10 - 13 is too limiting for an international phone number field; you're almost certain to find valid numbers that are both longer and shorter than this. I'd suggest a range of 8 - 20 to be safe.

[EDIT] OP states the above regex doesn't work due to the escape sequence. Not sure why, but an alternative would be:

^[+][0-9]{10,13}$ 

[EDIT 2] OP now adds that the + sign should be optional. In this case, the regex needs a question mark after the +, so the example above would now look like this:

^[+]?[0-9]{10,13}$