Concatenating string literals in Dart

UPDATE: Dart now supports the + concatenator for string.

Dart supports multiple ways to concatenate strings: string interpolation, the + operator, and adjacent string literals.

It turns out that puzzles arise from the using + to concatenate strings, so the Dart team felt compelled to take a fresh approach. Dart already had string interpolation, which allows you to embed a string within a string:

// String interpolation in Dart
String to = 'Bob';
String msg = "Hello $to";  // Hello Bob

Dart also has multi-line Strings, using triple quotes:

String htmlTemplate = """
<div>
  <p>
    Hello $to.
  </p>
</div>""";

Sometimes, however, you need to deal with very long strings. You can use the + operator to concat long strings, or use adjacent string literals.

// This works
String longMessage = 'This is what you used to do in Dart. ' +
                     'You would use the + operator ' +
                     'to concat strings. Just like we are ' +
                     'doing here, in fact.';

 // So does this
String longMessage = 'This is what you used to do in Dart. '
                     'You would use the + operator '
                     'to concat strings. Just like we are '
                     'doing here, in fact.';

Summary

You can concatenate strings with +, adjacent string literals, and string interpolation.

As always, the Dart team is very interested in your comments, please join the mailing list to share your experiences.

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