How to remove only symbols from string in dart

Question

I want to remove all special symbols from string and have only words in string I tried this but it gives same output only

main() {     String s = "Hello, world! i am 'foo'";     print(s.replaceAll(new RegExp('\W+'),''));  } 

output : Hello, world! i am 'foo'
expected : Hello world i am foo

Answer 1

There are two issues:

• '\W' is not a valid escape sequence, to define a backslash in a regular string literal, you need to use \\, or use a raw string literal (r'...')
• \W regex pattern matches any char that is not a word char including whitespace, you need to use a negated character class with word and whitespace classes, [^\w\s].

Use

void main() {   String s = "Hello, world! i am 'foo'";   print(s.replaceAll(new RegExp(r'[^\w\s]+'),'')); } 

Output: Hello world i am foo.

Fully Unicode-aware solution

Based on What's the correct regex range for javascript's regexes to match all the non word characters in any script? post, bearing in mind that \w in Unicode aware regex is equal to [\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}], you can use the following in Dart:

void main() {   String s = "Hęllo, wórld! i am 'foo'";   String regex = r'[^\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}\s]+';   print(s.replaceAll(RegExp(regex, unicode: true),'')); } // => Hęllo wórld i am foo