Add dart tutorials source code

Author: Frezyx

README.md

@@ -24,3 +24,20 @@ All source code from <a href="https://www.youtube.com/playlist?list=PLtUuja72DaL
 <p align="center"><a href="https://github.com/Frezyx/flutter_tutorials/tree/main/crypto_coins_list">Source code</a></p>
 
 
+## 2) Dart for beginners course (ru)
+Язык программирования Dart - темная лошадка от Google. 
+
+Если серьезно Dart - это язык, на котором можно писать что угодно, но в основном его используют для написания Flutter-приложений. Приложения на фреймворке Flutter имеют одну замечательную особенность - настоящая мультиплатформенность. 
+
+Это означает что написав код один раз - вы сможете запустить приложение на любой платформе и операционной системе (iOS, Android, Windows, Web...)  
+
+Даже если ты впервые в жизни взял клавиатуру в руки - смело включай курс и начинай изучать один из самых интересных и свежих  языков современности
+
+<a  href="https://www.youtube.com/watch?v=X4NJJF48o6c&list=PLtUuja72DaLLAo63Zsn1UsLONDafJKWrl&ab_channel=%D0%A1%D1%82%D0%B0%D1%81%D0%98%D0%BB%D1%8C%D0%B8%D0%BD"><img src="https://img.youtube.com/vi/dFNGGoQImUk/maxresdefault.jpg" alt="YouTube"></a>
+
+<p align="center">
+<a href="https://www.youtube.com/watch?v=X4NJJF48o6c&list=PLtUuja72DaLLAo63Zsn1UsLONDafJKWrl&ab_channel=%D0%A1%D1%82%D0%B0%D1%81%D0%98%D0%BB%D1%8C%D0%B8%D0%BD"><img src="https://img.shields.io/badge/YouTube-FF0000?style=for-the-badge&logo=youtube&logoColor=white" alt="YouTube"></a>
+<a href="https://t.me/frezycode"><img src="https://img.shields.io/badge/Telegram-2CA5E0?style=for-the-badge&logo=telegram&logoColor=white" alt="Telegram"></a>
+<a href="https://github.com/Frezyx/flutter_tutorials/tree/main/dart_tutorials"><img src="https://img.shields.io/badge/GitHub-100000?style=for-the-badge&logo=github&logoColor=white" alt="GitHub"></a>
+</p>
+<p align="center"><a href="https://github.com/Frezyx/flutter_tutorials/tree/main/dart_tutorials">Source code</a></p>

dart_tutorials/exchange/.gitignore

@@ -0,0 +1,3 @@
+# https://dart.dev/guides/libraries/private-files
+# Created by `dart pub`
+.dart_tool/

dart_tutorials/exchange/CHANGELOG.md

@@ -0,0 +1,3 @@
+## 1.0.0
+
+- Initial version.

dart_tutorials/exchange/README.md

@@ -0,0 +1,2 @@
+A sample command-line application with an entrypoint in `bin/`, library code
+in `lib/`, and example unit test in `test/`.

dart_tutorials/exchange/analysis_options.yaml

@@ -0,0 +1,30 @@
+# This file configures the static analysis results for your project (errors,
+# warnings, and lints).
+#
+# This enables the 'recommended' set of lints from `package:lints`.
+# This set helps identify many issues that may lead to problems when running
+# or consuming Dart code, and enforces writing Dart using a single, idiomatic
+# style and format.
+#
+# If you want a smaller set of lints you can change this to specify
+# 'package:lints/core.yaml'. These are just the most critical lints
+# (the recommended set includes the core lints).
+# The core lints are also what is used by pub.dev for scoring packages.
+
+include: package:lints/recommended.yaml
+
+# Uncomment the following section to specify additional rules.
+
+# linter:
+#   rules:
+#     - camel_case_types
+
+# analyzer:
+#   exclude:
+#     - path/to/excluded/files/**
+
+# For more information about the core and recommended set of lints, see
+# https://dart.dev/go/core-lints
+
+# For additional information about configuring this file, see
+# https://dart.dev/guides/language/analysis-options

dart_tutorials/exchange/bin/exchange.dart

@@ -0,0 +1,38 @@
+import 'dart:convert';
+
+import 'package:http/http.dart' as http;
+
+Future<void> main(List<String> arguments) async {
+  if (arguments.length != 3) {
+    print('Неверный формат вызова');
+    print('Формат: exchange EUR GBP 1000');
+    return;
+  }
+  final fromCurrency = arguments[0];
+  final toCurrency = arguments[1];
+  final strAmount = arguments[2];
+  if (double.tryParse(strAmount) == null) {
+    print('Последним аргументом должна быть сумма');
+    return;
+  }
+  final amount = double.parse(strAmount);
+
+  print('Начал подсчет: $fromCurrency -> $toCurrency сумма: $amount');
+
+  final uri = Uri(
+    scheme: 'https',
+    host: 'api.exchangerate.host',
+    path: 'convert',
+    queryParameters: {
+      'from': fromCurrency,
+      'to': toCurrency,
+      'amount': amount.toString(),
+      'access_key': 'f80b67a9cebb4b434c72dcafa8520235',
+    },
+  );
+
+  final response = await http.get(uri);
+  final stringBody = response.body;
+  final data = JsonDecoder().convert(stringBody) as Map<String, dynamic>;
+  print(data['result']);
+}