What does colon mean when importing core libraries in Dart?

import 'dart:math';

I haven't find any resources that tells what does that mean.

CodePudding user response：

You should use colon when you try to import other packages modules... You can omit it when the module that you are importing is in the same package.

import '<package>:<module>'; // normal import
/* 
  if the module is the in the same package of the file where i'm importing it 
*/
import '<module>';

CodePudding user response：

From the documentation (emphasis mine):

Using libraries

Use import to specify how a namespace from one library is used in the scope of another library.

For example, Dart web apps generally use the dart:html library, which they can import like this:

import 'dart:html';

The only required argument to import is a URI specifying the library. For built-in libraries, the URI has the special dart: scheme. For other libraries, you can use a file system path or the package: scheme. The package: scheme specifies libraries provided by a package manager such as the pub tool. For example:

import 'package:test/test.dart';

Note: URI stands for uniform resource identifier. URLs (uniform resource locators) are a common kind of URI.