extension method Null safety

String extension(
  1. String path,
  2. [int level = 1]
)

Gets the file extension of path: the portion of basename from the last . to the end (including the . itself).

context.extension('path/to/foo.dart'); // -> '.dart'
context.extension('path/to/foo'); // -> ''
context.extension('path.to/foo'); // -> ''
context.extension('path/to/foo.dart.js'); // -> '.js'

If the file name starts with a ., then it is not considered an extension:

context.extension('~/.bashrc');    // -> ''
context.extension('~/.notes.txt'); // -> '.txt'

Takes an optional parameter level which makes possible to return multiple extensions having level number of dots. If level exceeds the number of dots, the full extension is returned. The value of level must be greater than 0, else RangeError is thrown.

context.extension('foo.bar.dart.js', 2);   // -> '.dart.js
context.extension('foo.bar.dart.js', 3);   // -> '.bar.dart.js'
context.extension('foo.bar.dart.js', 10);  // -> '.bar.dart.js'
context.extension('path/to/foo.bar.dart.js', 2);  // -> '.dart.js'

Implementation

String extension(String path, [int level = 1]) =>
    _parse(path).extension(level);