how to limit the number of characters entered?

Suppose I have this regular expression for a password : ^.(?=.{6,})(?=.[a-z])(?=.[A-Z]).$

The regular expression requires that the user enters at least 6 characters. So how can I limit the number of characters the user can enter?
So suppose I want to limit it to 50 characters. I have tried this, but it does not work, Notice how I added a 50 after the 6,:
 ^.(?=.{6,50})(?=.[a-z])(?=.[A-Z]).$
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brgdotnetcontractorAsked:
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käµfm³d 👽Commented:
To me, it makes more sense to have the length check on the part outside of the parens. The length of the string is a known item; whether or not your string contains an upper- or a lower-case letter is not. The latter belong in the lookaheads. I would modify your pattern thus:

 ^(?=[^a-z]*[a-z])(?=[A-Z]*[A-Z]).{6,50}$

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However, this leaves your password open to funky characters (like carriage returns, tabs, spaces, null characters, etc.). It is advisable for you to change the dot to a character class where you include all acceptable characters that your password can have.

e.g.

 ^(?=[^a-z]*[a-z])(?=[A-Z]*[A-Z])[a-zA-Z0-9$%#@]{6,50}$       (letters, numbers, dollar signs, percent signs, etc.)

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0
ozoCommented:
^(?=.{6,50}$)

but
(?=.[a-z])(?=.[A-Z])
is a contradiction
0

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Regular Expressions

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