RegEx: How to repeat pattern matched?

Question

I need to make sure that string matches rule that data matches following pattern

^\d{1,4}\,?

Basically it can be a list of numbers between 1-4 characters followed by ",". So this would be valid

1,12,123,1234 but 12345,123, would not. How does one tell it to repeat match? I tried grouping it and adding + at the end but that does not work.

Answer 1

请尝试以下操作：

/^(?:\d{1,4}(,|$))+$/

Answer 2

Regex should be using $ also to make sure entire input is matched and use quantifier + for repetition:

var re = /^(\d{1,4}(,|$))+$/;

And use RegExp.test method to validate the input:

var valid = re.test(str);

Testing:

re.test('1,12,123,1234');
true
re.test('12345,123');
false