正则表达式电话号码验证，使用空格和最小位数的字符

Question

I have less skill for the Regex and I have a quick question. I need to validate phone number input with regEx.

Explanation/expression will be really appreciated. The Phone numbers can be any of the following formats:

(94) 123 345
(94).456.7899
(94)-456-7899
94-456-7899
+94 456 7899
94 456 7899
0094 456 7899
(94) 123
122 3454
1223454

1) Number can include spaces and characters or without characters.
2) It should have minimum 5 digits without spaces and characters. (I stuck at this point)

1st try

export const basicPhoneNumber = value =>
value && !/^\+?\d+$/i.test(value) 
? 'Invalid phone number' 
: undefined;

2nd try

  export const basicPhoneNumber = value =>
  value && !/\(?([0-9]{3})\)?([ .-]?)([0-9]{3})\2([0-9]{4,})/i.test(value) 
  ? 'Invalid phone number' 
  : undefined;

Thanks a lot for all your help and have a good one!

Answer 1

Phone number validation with regular expression is rather complicated, especially in such cases, yet we can try with an expression similar to:

^\+?\(?([0-9]{2,4})[)\s.-]+([0-9]{3,4})([\s.-]+([0-9]{3,4}))?$

which would likely fail with some desired instances that are not listed, regardless that some inputs such as (000) 000-0000 are not really phone numbers.

 const regex = /^\\+?\\(?([0-9]{2,4})[)\\s.-]+([0-9]{3,4})([\\s.-]+([0-9]{3,4}))?$/gmi; const str = `(94) 123 345 (94).456.7899 (94)-456-7899 94-456-7899 +94 456 7899 94 456 7899 0094 456 7899 (94) 123 122 3454`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); } 

Demo 1

Edit

For allowing 12234554 , we would make an optional group for ([)\\s.-]+)? ,

^\+?\(?([0-9]{2,4})([)\s.-]+)?([0-9]{3,4})([\s.-]+([0-9]{3,4}))?$

Demo 2

Answer 2

If all you need to do is to validate the phone numbers with your listed criteria, you can consider stripping out all non-digit characters first, then test with RegExp.

Not only it is a lot easier, it is also much easier to understand.

 // Sample data const numbers = [ '(94) 123 345', '(94).456.7899', '(94)-456-7899', '94-456-7899', '+94 456 7899', '94 456 7899', '0094 456 7899', '(94) 123', '122 3454' ] // The validation function const validate = value => { value = value.replace(/\\D|(^0+)/g, ''); return /^\\d{5,}$/.test(value); } // Tests numbers.forEach(function(phone){ console.log(validate(phone), `"${phone}"`); }); 

RegExp explanation:

/\\D|(^0+)/g

1. \\D matches all non-digit character.
2. (^0+) matches when there is at least 1 leading 0 character(s).

/^\\d{5,}$/

Matches when the string starts and ends with a digit, and when the string consists of at least 5 digits, without any non-digits.