Dart strings support interpolation, which allows you to embed expressions within a
string.
String expression = 'words';
print('A string containing ${expression}');
When the expression is a simple identifier, and the identifier is followed in the string interpolation by a character which is not allowed in an
identifier (e.g. whitespace, :, - but not a letter, digit, _, …), you can omit the curly braces.
This makes the code more readable and concise.
String expression = 'words';
print('A string containing $expression');
