CODEWITHSUNDEEP
regexregular-language
j2emanue
j2emanue

Reputation: 62549

Regular expression to filter special characters not working

i am searching for a regular expression i can use to check if a user input contains special characters in a specified list.

Here are the special characters not allowed by using a regular expression i tried to write: ^[`~!@#$%^&*()_+={}\[\]|\\:;“’<,>.?๐฿]*$

i went to https://regex101.com/ and i was expecting the following input to match but did it not why:

127 elmer road ??<>()

so in android java (but an be any ) i wrote the following function but it also always returns true . how can i filter all these special characters . I want a function that returns true if a given string does NOT match. 

  public boolean isValid( EditText et) {
            String string = et.getText().toString();
            boolean isValid = true;

             final Pattern sPattern
                    = Pattern.compile("^[`~!@#$%^&*()_+={}\\[\\]|\\\\:;“’<,>.?๐฿]*$");

            isValid=  !sPattern.matcher(string).matches();


            return isValid;
        }

update: i tried the following also:

enter image description here

Upvotes: 2

Views: 15308

Answers (1)

omijn
omijn

Reputation: 656

I want a function that returns true if a given string does NOT match.

You can negate the character set. (Note the ^ symbol within the square brackets). This will return true for strings that don't contain any of these special characters.

^[^`~!@#$%^&*()_+={}\[\]|\\:;“’<,>.?๐฿]*$

https://regex101.com/r/CqtqoK/1

Upvotes: 5

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