regex issue c# numbers are underscores now

Question

My Regex is removing all numeric (0-9) in my string. I don't get why all numbers are replaced by _

EDIT: I understand that my "_" regex pattern changes the characters into underscores. But not why numbers!

Can anyone help me out? I only need to remove like all special characters.

See regex here:

 string symbolPattern = "[!@#$%^&*()-=+`~{}'|]";
Regex.Replace("input here 12341234" , symbolPattern, "_");

Output: "input here ________"

Answer 1

The problem is your pattern uses a dash in the middle, which acts as a range of the ascii characters from ) to = . Here's a breakdown:

• ) : 41
• 1 : 49
• = : 61

As you can see, numbers start at 49, and falls between the range of 41-61, so they're matched and replaced.

You need to place the - at either the beginning or end of the character class for it to be matched literally rather than act as a range:

"[-!@#$%^&*()=+`~{}'|]"

Answer 2

你必须逃避-因为sequence [)-=]包含数字

string symbolPattern = "[!@#$%^&*()\-=+`~{}'|]";

Answer 3

Move the - to the end of the list so it is seen as a literal:

"[!@#$%^&*()=+`~{}'|-]"

Or, to the front :

"[-!@#$%^&*()=+`~{}'|]"

As it stands, it will match all characters in the range )-= , which includes all numerals.

Answer 4

You need to escape your special characters in your regex. For instance, * is a wildcard match. Look at what some of those special characters mean for your match.

Answer 5

I've not used C#, but typically the "*" character is also a control character that would need escaping.

The following matches a whole line of any characters, although the "^" and "$" are some what redundant:

^.*$

This matches any number of "A" characters that appear in a string:

A*

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