javascript - Regex for validating decimal number with fixed range -

i require regex validate fixed range decimal numbers e.g. 1234.1234 - valid, 4444.1234 - valid 123.123 - invalid, 1234.123 - invalid

the number 4 digit before decimal , 4 digit after decimal valid. i'm uses regex - /^\s((\d{4})((\.\d{4})?))$/ not satisfies me.

^\d{4}(\.\d{4})?$ 

this should you.use

^[1-9]\d{3}(\.\d{4})?$ 

if dont want match 0234.1234