Need assistance with regex -

Need assistance with regex -

for regex, want letters a-z 1-4 times followed digit 4-7 times. combination of these 2 should have 8 characters total.

([a-z]{1,4}[0-9]{4,7}){8}

i know wrong. can tell me right regex look create work

you can utilize lookahead based regular look assert string length 8 characters.

^(?=.{8}$)[a-z]{1,4}\d{4,7}$

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regex