【Flutter/Dart】for文/繰り返し文の使い方/基礎から実践

void main() {
  for (int i = 0; i < 5; i++) {
    print('hello${i + 1}');
  }
}

void main() {
  var mixFruit = ['apple', 'banana', 'grape'];
  for (var fruit in mixFruit) {
    print(fruit);
  }
  print('Loopから脱出');
}

void main(){
var mixFruit = ['apple', 'banana', 'grape'];

mixFruit.forEach((fruit){
    print(fruit);
  }
);
print('Loopから脱出');
}

void main() {
  var numbers = [1, 2, 3, 4, 5];
  
  numbers.forEach((num) {
    print(num);
  });
}

void main() {
  var ages = {
    'Alex': 18,
    'Ben': 15,
    'Charlie': 25,
  };
  ages.forEach((name, age) {
    print("${name} is ${age} years old");
  });
  print('Loopから脱出');
}

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'for文';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const MyStatelessWidget(),
      ),
    );
  }
}

class MyStatelessWidget extends StatelessWidget {

  const MyStatelessWidget({Key? key}) : super(key: key);



  @override
  Widget build(BuildContext context) {

     const moviesTitles = ['Inception', 'Heat', 'Spider Man'];


        return Column(
    children: moviesTitles.map((title) => Tab(text: title)).toList(),
    );
  }
}

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'BottomNavBar Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      title: _title,
      home: MyStatefulWidget(),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  int _selectedIndex = 0;

  void _onItemTapped(int index) {
    setState(() {
      _selectedIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('BottomNavigationBar Sample'),
      ),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children:<Widget>
        [
          Text(
          "indexNum: $_selectedIndex",
          style: const TextStyle(fontSize: 30, fontWeight: FontWeight.bold),
        ),
            for(int i = 0; i < 5; i++) ... {
              Text('${i}番目のループ。navigationbar${_selectedIndex}です。')
            },])
      ),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: _selectedIndex,
        onTap: _onItemTapped,
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.book),
            activeIcon: Icon(Icons.book_online),
            label: 'Book',
            tooltip: "This is a Book Page",
            backgroundColor: Colors.blue,

          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.business),
            activeIcon: Icon(Icons.business_center),
            label: 'Business',
            tooltip: "This is a Business Page",
            backgroundColor: Colors.green,
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.school),
            activeIcon: Icon(Icons.school_outlined),
            label: 'School',
            tooltip: "This is a School Page",
            backgroundColor: Colors.purple,
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.settings),
            activeIcon: Icon(Icons.settings_accessibility),
            label: 'Settings',
            tooltip: "This is a Settings Page",
            backgroundColor: Colors.pink,
          ),
        ],

        type: BottomNavigationBarType.shifting,
        // ここで色を設定していても、shiftingにしているので
        // Itemの方のbackgroundColorが勝ちます。
        backgroundColor: Colors.red,
        enableFeedback: true,
        // IconTheme系統の値が優先されます。
        iconSize: 18,
        // 横向きレイアウトは省略します。
        // landscapeLayout: 省略
        selectedFontSize: 20,
        selectedIconTheme: const IconThemeData(size: 30, color: Colors.green),
        selectedLabelStyle: const TextStyle(color: Colors.red),
        // ちなみに、LabelStyleとItemColorの両方を選択した場合、ItemColorが勝ちます。
        selectedItemColor: Colors.black,
        unselectedFontSize: 15,
        unselectedIconTheme: const IconThemeData(size: 25, color: Colors.white),
        unselectedLabelStyle: const TextStyle(color: Colors.purple),
        // IconTheme系統の値が優先されるのでこの値は適応されません。
        unselectedItemColor: Colors.red,
      ),
    );
  }
}