RegEx 允许所有字符，长度应为 1-50 个字符

Question

Issue

I am trying to implement a Regular Expression that will check a string is between 1 - 50 characters. They are allowed to enter any characters.

I am new to creating regex expressions but this is my attempt: ^{1,50}$

The reason I tried that is that I found this was the way to limit the characters.

Any help on this would be great.

Answer 1

Try ^.{1,50}$

Explanation:

• . dot stands for all characters. Except \\n for which you will have to use s DOTALL flag.

Regex101 Demo

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Answer 2

For the Exact Length of the String you could use

^.{50}$

Whereas to check the Length Range you can use

^.{5,50}$

It might be more sensible for real users if I also included a lower limit on the number of letters

If you wanted to just check the Minimum Length you can use

^.{50,}$

Now a string of at least fifty letters, but extending to any length,

^.{0,50}$

This will match a whole string containing between 0 and 50 (inclusive) of any character. Though regular expressions are probably the wrong tool for this job. Regex is overkill , just check the length of the string. You should have used String.Length for this like

if(UrString.Length > 0 && UrString.Length <= 50)

Answer 3

How about just inspecting the Length of the string?

string str = "less than 50 chars";
if(str.Length > 0 && str.Length <= 50)
{
    // yay, we've got a winner
}

Answer 4

I suggest

.{1,50}

To generate regex expressions you can use Expresso , which is a free .NET regular expression development tool. Using this program, you will be able to build complex regular expressions just by selecting its different components from a menu. You can test the created expressions entering values to them.

Answer 5

To allow all characters you use . in regex.

So, to have a max 50 char string you'd do:

^.{1,50}$