Regex number pattern in a fixed length

Question

I need to validate a field with a fixed length of 8 and it only accept numbers, like 12345678 or 11111118 (these are valid).

But I cannot accept when all numbers are the same, like 11111111

I came with ^\d{8}(\1*)$ https://regex101.com/r/tH2hB7/1 , but I can´t find the correct pattern to identify the repeating numbers

vks · Accepted Answer · 2016-09-16 18:23:31Z

4

You can add lookahead for the same. See demo.

^(\d)(?!\1{7}$)\d{7}$

answered Sep 16, 2016 at 18:23

vks

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