{"id":3176,"date":"2025-10-18T18:59:03","date_gmt":"2025-10-18T09:59:03","guid":{"rendered":"https:\/\/www.blowfish.co.jp\/?p=3176"},"modified":"2025-10-18T18:59:03","modified_gmt":"2025-10-18T09:59:03","slug":"%e7%ac%ac2%e7%ab%a0-%e5%9f%ba%e6%9c%ac%e6%96%87%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.blowfish.co.jp\/?p=3176","title":{"rendered":"\u7b2c2\u7ae0 \u57fa\u672c\u6587\u6cd5"},"content":{"rendered":"\n

\u5909\u6570\u3068\u5b9a\u6570\uff08var, final, const\uff09<\/h2>\n\n\n\n

Dart\u3067\u306f\u3001\u30c7\u30fc\u30bf\u3092\u683c\u7d0d\u3059\u308b\u305f\u3081\u306b\u5909\u6570\u3068\u5b9a\u6570\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n\n\n\n

var – \u578b\u63a8\u8ad6\u306b\u3088\u308b\u5909\u6570\u5ba3\u8a00<\/h3>\n\n\n\n
void main() {\n  var name = '\u592a\u90ce';  \/\/ String\u3068\u63a8\u8ad6\u3055\u308c\u308b\n  var age = 25;       \/\/ int\u3068\u63a8\u8ad6\u3055\u308c\u308b\n  var height = 175.5; \/\/ double\u3068\u63a8\u8ad6\u3055\u308c\u308b\n  \n  print('$name ($age\u6b73) \u8eab\u9577: $height cm');\n  \n  \/\/ \u5024\u306e\u5909\u66f4\u304c\u53ef\u80fd\n  age = 26;\n  print('\u8a95\u751f\u65e5\u3092\u8fce\u3048\u307e\u3057\u305f\u3002\u5e74\u9f62: $age');\n}\n<\/code><\/pre>\n\n\n\n
\u660e\u793a\u7684\u306a\u578b\u5ba3\u8a00<\/h3>\n\n\n\n
void main() {\n  String name = '\u82b1\u5b50';\n  int score = 95;\n  double temperature = 36.5;\n  bool isStudent = true;\n  \n  print('\u540d\u524d: $name, \u70b9\u6570: $score, \u4f53\u6e29: $temperature\u2103');\n}\n<\/code><\/pre>\n\n\n\n
final – \u5b9f\u884c\u6642\u306b\u4e00\u5ea6\u3060\u3051\u8a2d\u5b9a\u3055\u308c\u308b\u5b9a\u6570<\/h3>\n\n\n\n
void main() {\n  final currentTime = DateTime.now(); \/\/ \u5b9f\u884c\u6642\u306b\u6c7a\u5b9a\n  final pi = 3.14159;\n  \n  print('\u73fe\u5728\u6642\u523b: $currentTime');\n  \n  \/\/ \u30a8\u30e9\u30fc\uff1afinal\u306f\u518d\u4ee3\u5165\u3067\u304d\u306a\u3044\n  \/\/ currentTime = DateTime.now();\n}\n<\/code><\/pre>\n\n\n\n
const – \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u5b9a\u6570<\/h3>\n\n\n\n
void main() {\n  const pi = 3.14159;           \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u6c7a\u5b9a\n  const appName = 'MyApp';\n  const maxUsers = 100;\n  \n  print('\u5186\u5468\u7387: $pi');\n  \n  \/\/ \u30a8\u30e9\u30fc\uff1aconst\u306f\u518d\u4ee3\u5165\u3067\u304d\u306a\u3044\n  \/\/ pi = 3.14;\n  \n  \/\/ \u30a8\u30e9\u30fc\uff1aconst\u306f\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u5024\u304c\u78ba\u5b9a\u3057\u3066\u3044\u308b\u5fc5\u8981\u304c\u3042\u308b\n  \/\/ const now = DateTime.now();\n}\n<\/code><\/pre>\n\n\n\n
var\u3001final\u3001const\u306e\u4f7f\u3044\u5206\u3051<\/h3>\n\n\n\n
\u30ad\u30fc\u30ef\u30fc\u30c9<\/th>\u518d\u4ee3\u5165<\/th>\u6c7a\u5b9a\u6642\u671f<\/th>\u4f7f\u7528\u5834\u9762<\/th><\/tr><\/thead>
var<\/strong><\/td>\u53ef\u80fd<\/td>\u5b9f\u884c\u6642<\/td>\u5024\u304c\u5909\u66f4\u3055\u308c\u308b\u5909\u6570<\/td><\/tr>
final<\/strong><\/td>\u4e0d\u53ef<\/td>\u5b9f\u884c\u6642<\/td>\u4e00\u5ea6\u8a2d\u5b9a\u3057\u305f\u3089\u5909\u66f4\u3057\u306a\u3044\u5024<\/td><\/tr>
const<\/strong><\/td>\u4e0d\u53ef<\/td>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642<\/td>\u5b8c\u5168\u306b\u56fa\u5b9a\u3055\u308c\u305f\u5b9a\u6570<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u30c7\u30fc\u30bf\u578b\uff08int, double, String, bool\uff09<\/h2>\n\n\n\n
int – \u6574\u6570\u578b<\/h3>\n\n\n\n
void main() {\n  int age = 25;\n  int negative = -10;\n  int hex = 0xFF;  \/\/ 16\u9032\u6570: 255\n  \n  print('\u5e74\u9f62: $age');\n  print('16\u9032\u65700xFF\u306f10\u9032\u6570\u3067: $hex');\n  \n  \/\/ \u6f14\u7b97\n  int sum = 10 + 20;\n  int product = 5 * 6;\n  int quotient = 10 ~\/ 3;  \/\/ \u6574\u6570\u9664\u7b97: 3\n  int remainder = 10 % 3;   \/\/ \u5270\u4f59: 1\n  \n  print('\u5546: $quotient, \u4f59\u308a: $remainder');\n}\n<\/code><\/pre>\n\n\n\n
double – \u6d6e\u52d5\u5c0f\u6570\u70b9\u6570\u578b<\/h3>\n\n\n\n
void main() {\n  double pi = 3.14159;\n  double temperature = 36.5;\n  double scientific = 1.5e3;  \/\/ 1.5 \u00d7 10^3 = 1500.0\n  \n  print('\u5186\u5468\u7387: $pi');\n  print('\u79d1\u5b66\u7684\u8a18\u6cd5: $scientific');\n  \n  \/\/ \u6f14\u7b97\n  double result = 10.0 \/ 3.0;  \/\/ 3.3333...\n  print('10 \u00f7 3 = $result');\n  \n  \/\/ \u7cbe\u5ea6\u6307\u5b9a\n  print('\u5c0f\u6570\u70b9\u4ee5\u4e0b2\u6841: ${result.toStringAsFixed(2)}');\n}\n<\/code><\/pre>\n\n\n\n
num – int\u3068double\u306e\u5171\u901a\u89aa\u578b<\/h3>\n\n\n\n
void main() {\n  num value1 = 10;      \/\/ int\u3092\u4ee3\u5165\u53ef\u80fd\n  num value2 = 3.14;    \/\/ double\u3092\u4ee3\u5165\u53ef\u80fd\n  \n  print('value1: $value1 (${value1.runtimeType})');\n  print('value2: $value2 (${value2.runtimeType})');\n}\n<\/code><\/pre>\n\n\n\n
String – \u6587\u5b57\u5217\u578b<\/h3>\n\n\n\n
void main() {\n  String name = '\u5c71\u7530\u592a\u90ce';\n  String greeting = \"\u3053\u3093\u306b\u3061\u306f\";  \/\/ \u30b7\u30f3\u30b0\u30eb\u30fb\u30c0\u30d6\u30eb\u4e21\u65b9\u53ef\n  \n  \/\/ \u6587\u5b57\u5217\u88dc\u9593\n  String message = '$greeting\u3055\u3093\u3001$name\u3067\u3059';\n  print(message);\n  \n  \/\/ \u5f0f\u306e\u57cb\u3081\u8fbc\u307f\n  int age = 25;\n  print('\u6765\u5e74\u306f${age + 1}\u6b73\u306b\u306a\u308a\u307e\u3059');\n  \n  \/\/ \u8907\u6570\u884c\u6587\u5b57\u5217\n  String multiline = '''\n  \u3053\u308c\u306f\n  \u8907\u6570\u884c\u306e\n  \u6587\u5b57\u5217\u3067\u3059\n  ''';\n  print(multiline);\n  \n  \/\/ \u6587\u5b57\u5217\u306e\u9023\u7d50\n  String fullName = '\u5c71\u7530' + '\u592a\u90ce';\n  String fullName2 = '\u5c71\u7530' '\u592a\u90ce';  \/\/ \u96a3\u63a5\u3059\u308b\u6587\u5b57\u5217\u306f\u81ea\u52d5\u9023\u7d50\n  \n  \/\/ \u6587\u5b57\u5217\u306e\u30e1\u30bd\u30c3\u30c9\n  print('\u9577\u3055: ${name.length}');\n  print('\u5927\u6587\u5b57: ${'hello'.toUpperCase()}');\n  print('\u542b\u307e\u308c\u308b: ${'hello world'.contains('world')}');\n  print('\u5206\u5272: ${'apple,banana,orange'.split(',')}');\n}\n<\/code><\/pre>\n\n\n\n
bool – \u771f\u507d\u5024\u578b<\/h3>\n\n\n\n
void main() {\n  bool isStudent = true;\n  bool hasLicense = false;\n  \n  print('\u5b66\u751f\u3067\u3059\u304b\uff1f: $isStudent');\n  \n  \/\/ \u6bd4\u8f03\u6f14\u7b97\u306e\u7d50\u679c\u3082bool\n  bool isAdult = 20 >= 18;\n  print('\u6210\u4eba\u3067\u3059\u304b\uff1f: $isAdult');\n  \n  \/\/ \u8ad6\u7406\u6f14\u7b97\n  bool canDrive = isAdult && hasLicense;\n  print('\u904b\u8ee2\u3067\u304d\u307e\u3059\u304b\uff1f: $canDrive');\n}\n<\/code><\/pre>\n\n\n\n
\u578b\u5909\u63db<\/h3>\n\n\n\n
void main() {\n  \/\/ String \u2192 int\/double\n  String numStr = '123';\n  int num1 = int.parse(numStr);\n  double num2 = double.parse('3.14');\n  \n  print('\u5909\u63db\u7d50\u679c: $num1, $num2');\n  \n  \/\/ int\/double \u2192 String\n  int age = 25;\n  String ageStr = age.toString();\n  String ageStr2 = '$age';  \/\/ \u3088\u308a\u7c21\u6f54\n  \n  print('\u6587\u5b57\u5217\u5316: $ageStr');\n  \n  \/\/ int \u21d4 double\n  int intValue = 10;\n  double doubleValue = intValue.toDouble();\n  \n  double pi = 3.14;\n  int truncated = pi.toInt();  \/\/ 3\uff08\u5207\u308a\u6368\u3066\uff09\n  int rounded = pi.round();    \/\/ 3\uff08\u56db\u6368\u4e94\u5165\uff09\n  \n  print('\u5207\u308a\u6368\u3066: $truncated, \u56db\u6368\u4e94\u5165: $rounded');\n}\n<\/code><\/pre>\n\n\n\n
\u6f14\u7b97\u5b50<\/h2>\n\n\n\n
\u7b97\u8853\u6f14\u7b97\u5b50<\/h3>\n\n\n\n
void main() {\n  int a = 10, b = 3;\n  \n  print('\u52a0\u7b97: ${a + b}');      \/\/ 13\n  print('\u6e1b\u7b97: ${a - b}');      \/\/ 7\n  print('\u4e57\u7b97: ${a * b}');      \/\/ 30\n  print('\u9664\u7b97: ${a \/ b}');      \/\/ 3.333... (double)\n  print('\u6574\u6570\u9664\u7b97: ${a ~\/ b}'); \/\/ 3 (int)\n  print('\u5270\u4f59: ${a % b}');      \/\/ 1\n  \n  \/\/ \u5358\u9805\u6f14\u7b97\u5b50\n  int c = 5;\n  print('\u8ca0\u6570: ${-c}');         \/\/ -5\n  \n  \/\/ \u30a4\u30f3\u30af\u30ea\u30e1\u30f3\u30c8\u30fb\u30c7\u30af\u30ea\u30e1\u30f3\u30c8\n  int d = 10;\n  print('\u5f8c\u7f6e: ${d++}');        \/\/ 10 (\u4f7f\u7528\u5f8c\u306b\u5897\u52a0)\n  print('\u7d50\u679c: $d');            \/\/ 11\n  \n  int e = 10;\n  print('\u524d\u7f6e: ${++e}');        \/\/ 11 (\u5897\u52a0\u5f8c\u306b\u4f7f\u7528)\n  print('\u7d50\u679c: $e');            \/\/ 11\n}\n<\/code><\/pre>\n\n\n\n
\u6bd4\u8f03\u6f14\u7b97\u5b50<\/h3>\n\n\n\n
void main() {\n  int x = 10, y = 20;\n  \n  print('\u7b49\u3057\u3044: ${x == y}');           \/\/ false\n  print('\u7b49\u3057\u304f\u306a\u3044: ${x != y}');       \/\/ true\n  print('\u3088\u308a\u5927\u304d\u3044: ${x > y}');        \/\/ false\n  print('\u3088\u308a\u5c0f\u3055\u3044: ${x < y}');        \/\/ true\n  print('\u4ee5\u4e0a: ${x >= 10}');            \/\/ true\n  print('\u4ee5\u4e0b: ${y <= 20}');            \/\/ true\n}\n<\/code><\/pre>\n\n\n\n
\u8ad6\u7406\u6f14\u7b97\u5b50<\/h3>\n\n\n\n
void main() {\n  bool a = true, b = false;\n  \n  print('AND: ${a && b}');     \/\/ false\n  print('OR: ${a || b}');      \/\/ true\n  print('NOT: ${!a}');         \/\/ false\n  \n  \/\/ \u77ed\u7d61\u8a55\u4fa1\n  int? value = null;\n  bool result = value != null && value > 10;\n  print('\u77ed\u7d61\u8a55\u4fa1: $result');  \/\/ false (value > 10\u306f\u8a55\u4fa1\u3055\u308c\u306a\u3044)\n}\n<\/code><\/pre>\n\n\n\n
\u4ee3\u5165\u6f14\u7b97\u5b50<\/h3>\n\n\n\n
void main() {\n  int a = 10;\n  \n  a += 5;   \/\/ a = a + 5\n  print('+=: $a');  \/\/ 15\n  \n  a -= 3;   \/\/ a = a - 3\n  print('-=: $a');  \/\/ 12\n  \n  a *= 2;   \/\/ a = a * 2\n  print('*=: $a');  \/\/ 24\n  \n  a ~\/= 5;  \/\/ a = a ~\/ 5\n  print('~\/=: $a'); \/\/ 4\n  \n  \/\/ Null\u5408\u4f53\u4ee3\u5165\u6f14\u7b97\u5b50\n  String? name;\n  name ??= '\u540d\u524d\u306a\u3057';  \/\/ name\u304cnull\u306e\u5834\u5408\u306e\u307f\u4ee3\u5165\n  print('name: $name'); \/\/ \u540d\u524d\u306a\u3057\n}\n<\/code><\/pre>\n\n\n\n
\u6761\u4ef6\u6f14\u7b97\u5b50\uff08\u4e09\u9805\u6f14\u7b97\u5b50\uff09<\/h3>\n\n\n\n
void main() {\n  int age = 20;\n  String status = age >= 18 ? '\u6210\u4eba' : '\u672a\u6210\u5e74';\n  print('\u30b9\u30c6\u30fc\u30bf\u30b9: $status');\n  \n  \/\/ Null\u5408\u4f53\u6f14\u7b97\u5b50\n  String? username = null;\n  String displayName = username ?? '\u30b2\u30b9\u30c8';\n  print('\u8868\u793a\u540d: $displayName');  \/\/ \u30b2\u30b9\u30c8\n}\n<\/code><\/pre>\n\n\n\n
\u30ab\u30b9\u30b1\u30fc\u30c9\u8a18\u6cd5<\/h3>\n\n\n\n
class Person {\n  String? name;\n  int? age;\n  \n  void introduce() {\n    print('$name\u3067\u3059\u3002$age\u6b73\u3067\u3059\u3002');\n  }\n}\n\nvoid main() {\n  \/\/ \u901a\u5e38\u306e\u65b9\u6cd5\n  var person1 = Person();\n  person1.name = '\u592a\u90ce';\n  person1.age = 25;\n  person1.introduce();\n  \n  \/\/ \u30ab\u30b9\u30b1\u30fc\u30c9\u8a18\u6cd5\n  var person2 = Person()\n    ..name = '\u82b1\u5b50'\n    ..age = 23\n    ..introduce();\n}\n<\/code><\/pre>\n\n\n\n
\u5236\u5fa1\u69cb\u6587\uff08if, switch, for, while\uff09<\/h2>\n\n\n\n
if\u6587<\/h3>\n\n\n\n
void main() {\n  int score = 85;\n  \n  \/\/ \u57fa\u672c\u7684\u306aif\u6587\n  if (score >= 80) {\n    print('\u512a\u79c0\u3067\u3059');\n  }\n  \n  \/\/ if-else\n  if (score >= 60) {\n    print('\u5408\u683c');\n  } else {\n    print('\u4e0d\u5408\u683c');\n  }\n  \n  \/\/ if-else if-else\n  if (score >= 90) {\n    print('\u8a55\u4fa1: A');\n  } else if (score >= 80) {\n    print('\u8a55\u4fa1: B');\n  } else if (score >= 70) {\n    print('\u8a55\u4fa1: C');\n  } else if (score >= 60) {\n    print('\u8a55\u4fa1: D');\n  } else {\n    print('\u8a55\u4fa1: F');\n  }\n  \n  \/\/ \u6761\u4ef6\u5f0f\n  String result = score >= 60 ? '\u5408\u683c' : '\u4e0d\u5408\u683c';\n  print(result);\n}\n<\/code><\/pre>\n\n\n\n
switch\u6587<\/h3>\n\n\n\n
void main() {\n  String grade = 'B';\n  \n  \/\/ \u57fa\u672c\u7684\u306aswitch\u6587\n  switch (grade) {\n    case 'A':\n      print('\u7d20\u6674\u3089\u3057\u3044\uff01');\n      break;\n    case 'B':\n      print('\u826f\u597d\u3067\u3059');\n      break;\n    case 'C':\n      print('\u666e\u901a\u3067\u3059');\n      break;\n    default:\n      print('\u8a55\u4fa1\u306a\u3057');\n  }\n  \n  \/\/ \u8907\u6570\u306ecase\u3092\u307e\u3068\u3081\u308b\n  int dayOfWeek = 6;\n  \n  switch (dayOfWeek) {\n    case 1:\n    case 2:\n    case 3:\n    case 4:\n    case 5:\n      print('\u5e73\u65e5');\n      break;\n    case 6:\n    case 7:\n      print('\u9031\u672b');\n      break;\n    default:\n      print('\u4e0d\u6b63\u306a\u5024');\n  }\n  \n  \/\/ continue\u3092\u4f7f\u3063\u305f\u51e6\u7406\u306e\u7d99\u7d9a\n  String command = 'start';\n  \n  switch (command) {\n    case 'start':\n      print('\u958b\u59cb\u3057\u307e\u3059');\n      continue processing;  \/\/ processing\u30e9\u30d9\u30eb\u3078\u30b8\u30e3\u30f3\u30d7\n    processing:\n    case 'process':\n      print('\u51e6\u7406\u4e2d...');\n      break;\n    case 'stop':\n      print('\u505c\u6b62\u3057\u307e\u3059');\n      break;\n  }\n}\n<\/code><\/pre>\n\n\n\n
for\u6587<\/h3>\n\n\n\n
void main() {\n  \/\/ \u57fa\u672c\u7684\u306afor\u6587\n  print('=== \u57fa\u672c\u7684\u306afor\u6587 ===');\n  for (int i = 0; i < 5; i++) {\n    print('i = $i');\n  }\n  \n  \/\/ \u8907\u6570\u306e\u5909\u6570\n  print('\\n=== \u8907\u6570\u306e\u5909\u6570 ===');\n  for (int i = 0, j = 10; i < 5; i++, j--) {\n    print('i = $i, j = $j');\n  }\n  \n  \/\/ for-in\u6587\uff08\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u7528\uff09\n  print('\\n=== for-in\u6587 ===');\n  List<String> fruits = ['\u308a\u3093\u3054', '\u30d0\u30ca\u30ca', '\u30aa\u30ec\u30f3\u30b8'];\n  for (var fruit in fruits) {\n    print(fruit);\n  }\n  \n  \/\/ forEach\uff08\u95a2\u6570\u578b\uff09\n  print('\\n=== forEach ===');\n  fruits.forEach((fruit) {\n    print('\u597d\u304d\u306a\u679c\u7269: $fruit');\n  });\n  \n  \/\/ break \u3068 continue\n  print('\\n=== break \u3068 continue ===');\n  for (int i = 0; i < 10; i++) {\n    if (i == 3) continue;  \/\/ 3\u306f\u30b9\u30ad\u30c3\u30d7\n    if (i == 7) break;     \/\/ 7\u3067\u7d42\u4e86\n    print(i);\n  }\n}\n<\/code><\/pre>\n\n\n\n
while\u6587\u3068do-while\u6587<\/h3>\n\n\n\n
void main() {\n  \/\/ while\u6587\n  print('=== while\u6587 ===');\n  int count = 0;\n  while (count < 5) {\n    print('count: $count');\n    count++;\n  }\n  \n  \/\/ do-while\u6587\uff08\u6700\u4f4e1\u56de\u306f\u5b9f\u884c\u3055\u308c\u308b\uff09\n  print('\\n=== do-while\u6587 ===');\n  int num = 0;\n  do {\n    print('num: $num');\n    num++;\n  } while (num < 3);\n  \n  \/\/ \u6761\u4ef6\u304c\u6700\u521d\u304b\u3089\u507d\u306e\u5834\u5408\n  print('\\n=== \u6700\u521d\u304b\u3089\u6761\u4ef6\u304c\u507d ===');\n  int x = 10;\n  \n  \/\/ while\u6587\u306f\u5b9f\u884c\u3055\u308c\u306a\u3044\n  while (x < 5) {\n    print('\u3053\u308c\u306f\u8868\u793a\u3055\u308c\u307e\u305b\u3093');\n  }\n  \n  \/\/ do-while\u6587\u306f1\u56de\u5b9f\u884c\u3055\u308c\u308b\n  do {\n    print('x = $x\uff081\u56de\u3060\u3051\u5b9f\u884c\u3055\u308c\u308b\uff09');\n  } while (x < 5);\n}\n<\/code><\/pre>\n\n\n\n
\u30e9\u30d9\u30eb\u4ed8\u304d\u30eb\u30fc\u30d7<\/h3>\n\n\n\n
void main() {\n  \/\/ \u30cd\u30b9\u30c8\u3055\u308c\u305f\u30eb\u30fc\u30d7\u304b\u3089\u306e\u8131\u51fa\n  outer:\n  for (int i = 0; i < 3; i++) {\n    for (int j = 0; j < 3; j++) {\n      print('i=$i, j=$j');\n      if (i == 1 && j == 1) {\n        break outer;  \/\/ \u5916\u5074\u306e\u30eb\u30fc\u30d7\u3092\u629c\u3051\u308b\n      }\n    }\n  }\n  print('\u30eb\u30fc\u30d7\u7d42\u4e86');\n}\n<\/code><\/pre>\n\n\n\n
\u95a2\u6570\u306e\u57fa\u790e<\/h2>\n\n\n\n
\u57fa\u672c\u7684\u306a\u95a2\u6570\u5b9a\u7fa9<\/h3>\n\n\n\n
\/\/ \u623b\u308a\u5024\u3042\u308a\u306e\u95a2\u6570\nint add(int a, int b) {\n  return a + b;\n}\n\n\/\/ \u623b\u308a\u5024\u306a\u3057\u306e\u95a2\u6570\nvoid greet(String name) {\n  print('\u3053\u3093\u306b\u3061\u306f\u3001$name\u3055\u3093\uff01');\n}\n\n\/\/ \u30a2\u30ed\u30fc\u95a2\u6570\uff08\u5f0f\u304c1\u3064\u306e\u5834\u5408\uff09\nint multiply(int a, int b) => a * b;\n\nvoid main() {\n  int result = add(5, 3);\n  print('5 + 3 = $result');\n  \n  greet('\u592a\u90ce');\n  \n  print('5 \u00d7 3 = ${multiply(5, 3)}');\n}\n<\/code><\/pre>\n\n\n\n
\u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u5f15\u6570<\/h3>\n\n\n\n
\/\/ \u540d\u524d\u4ed8\u304d\u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u5f15\u6570\nvoid introduce({String name = '\u30b2\u30b9\u30c8', int age = 0}) {\n  print('\u540d\u524d: $name, \u5e74\u9f62: $age');\n}\n\n\/\/ \u5fc5\u9808\u306e\u540d\u524d\u4ed8\u304d\u5f15\u6570\uff08Dart 2.12\u4ee5\u964d\uff09\nvoid registerUser({required String email, required String password}) {\n  print('\u767b\u9332: $email');\n}\n\n\/\/ \u4f4d\u7f6e\u6307\u5b9a\u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u5f15\u6570\nString createMessage(String text, [String suffix = '']) {\n  return text + suffix;\n}\n\nvoid main() {\n  introduce();                          \/\/ \u540d\u524d: \u30b2\u30b9\u30c8, \u5e74\u9f62: 0\n  introduce(name: '\u592a\u90ce');              \/\/ \u540d\u524d: \u592a\u90ce, \u5e74\u9f62: 0\n  introduce(name: '\u82b1\u5b50', age: 25);    \/\/ \u540d\u524d: \u82b1\u5b50, \u5e74\u9f62: 25\n  \n  registerUser(email: 'test@example.com', password: 'secret');\n  \n  print(createMessage('\u3053\u3093\u306b\u3061\u306f'));           \/\/ \u3053\u3093\u306b\u3061\u306f\n  print(createMessage('\u3053\u3093\u306b\u3061\u306f', '\uff01'));    \/\/ \u3053\u3093\u306b\u3061\u306f\uff01\n}\n<\/code><\/pre>\n\n\n\n
\u95a2\u6570\u3092\u5909\u6570\u306b\u4ee3\u5165<\/h3>\n\n\n\n
void main() {\n  \/\/ \u95a2\u6570\u3092\u5909\u6570\u306b\u4ee3\u5165\n  var myFunction = (int x, int y) => x + y;\n  print('\u7d50\u679c: ${myFunction(10, 20)}');\n  \n  \/\/ \u95a2\u6570\u3092\u5f15\u6570\u3068\u3057\u3066\u6e21\u3059\n  void execute(int a, int b, Function operation) {\n    print('\u5b9f\u884c\u7d50\u679c: ${operation(a, b)}');\n  }\n  \n  execute(5, 3, (x, y) => x + y);  \/\/ \u5b9f\u884c\u7d50\u679c: 8\n  execute(5, 3, (x, y) => x * y);  \/\/ \u5b9f\u884c\u7d50\u679c: 15\n}\n<\/code><\/pre>\n\n\n\n
\u518d\u5e30\u95a2\u6570<\/h3>\n\n\n\n
\/\/ \u968e\u4e57\u3092\u8a08\u7b97\u3059\u308b\u518d\u5e30\u95a2\u6570\nint factorial(int n) {\n  if (n <= 1) return 1;\n  return n * factorial(n - 1);\n}\n\n\/\/ \u30d5\u30a3\u30dc\u30ca\u30c3\u30c1\u6570\u5217\nint fibonacci(int n) {\n  if (n <= 1) return n;\n  return fibonacci(n - 1) + fibonacci(n - 2);\n}\n\nvoid main() {\n  print('5\u306e\u968e\u4e57: ${factorial(5)}');      \/\/ 120\n  print('\u30d5\u30a3\u30dc\u30ca\u30c3\u30c1(10): ${fibonacci(10)}');  \/\/ 55\n}\n<\/code><\/pre>\n\n\n\n
\u30b3\u30e1\u30f3\u30c8\u3068\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3<\/h2>\n\n\n\n
\u30b3\u30e1\u30f3\u30c8\u306e\u7a2e\u985e<\/h3>\n\n\n\n
\/\/ \u3053\u308c\u306f\u4e00\u884c\u30b3\u30e1\u30f3\u30c8\u3067\u3059\n\n\/*\n  \u3053\u308c\u306f\n  \u8907\u6570\u884c\n  \u30b3\u30e1\u30f3\u30c8\u3067\u3059\n*\/\n\n\/\/\/ \u3053\u308c\u306f\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3\u30b3\u30e1\u30f3\u30c8\u3067\u3059\n\/\/\/ API\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u8868\u793a\u3055\u308c\u307e\u3059\nvoid exampleFunction() {\n  print('\u95a2\u6570\u306e\u5b9f\u884c');\n}\n\nvoid main() {\n  \/\/ \u5909\u6570\u306e\u5ba3\u8a00\n  var message = 'Hello'; \/\/ \u884c\u672b\u30b3\u30e1\u30f3\u30c8\n  \n  \/* \u4e00\u6642\u7684\u306b\u7121\u52b9\u5316\n  print('\u3053\u306e\u884c\u306f\u5b9f\u884c\u3055\u308c\u307e\u305b\u3093');\n  *\/\n  \n  print(message);\n}\n<\/code><\/pre>\n\n\n\n
\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3\u30b3\u30e1\u30f3\u30c8<\/h3>\n\n\n\n
\/\/\/ \u30e6\u30fc\u30b6\u30fc\u60c5\u5831\u3092\u8868\u3059\u30af\u30e9\u30b9\n\/\/\/ \n\/\/\/ \u3053\u306e\u30af\u30e9\u30b9\u306f\u540d\u524d\u3068\u5e74\u9f62\u3092\u4fdd\u6301\u3057\u307e\u3059\u3002\n\/\/\/ \u4f7f\u7528\u4f8b:\n\/\/\/ ```dart\n\/\/\/ var user = User('\u592a\u90ce', 25);\n\/\/\/ user.introduce();\n\/\/\/ ```\nclass User {\n  \/\/\/ \u30e6\u30fc\u30b6\u30fc\u306e\u540d\u524d\n  String name;\n  \n  \/\/\/ \u30e6\u30fc\u30b6\u30fc\u306e\u5e74\u9f62\n  int age;\n  \n  \/\/\/ \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n  \/\/\/ \n  \/\/\/ [name] \u30e6\u30fc\u30b6\u30fc\u306e\u540d\u524d\n  \/\/\/ [age] \u30e6\u30fc\u30b6\u30fc\u306e\u5e74\u9f62\uff080\u4ee5\u4e0a\uff09\n  User(this.name, this.age);\n  \n  \/\/\/ \u81ea\u5df1\u7d39\u4ecb\u3092\u8868\u793a\u3059\u308b\n  \/\/\/ \n  \/\/\/ \u30b3\u30f3\u30bd\u30fc\u30eb\u306b\u540d\u524d\u3068\u5e74\u9f62\u3092\u51fa\u529b\u3057\u307e\u3059\u3002\n  \/\/\/ \n  \/\/\/ \u4f8b:\n  \/\/\/ ```dart\n  \/\/\/ user.introduce();\n  \/\/\/ \/\/ \u51fa\u529b: \u592a\u90ce\u3067\u3059\u300225\u6b73\u3067\u3059\u3002\n  \/\/\/ ```\n  void introduce() {\n    print('$name\u3067\u3059\u3002$age\u6b73\u3067\u3059\u3002');\n  }\n}\n\n\/\/\/ 2\u3064\u306e\u6570\u5024\u3092\u52a0\u7b97\u3059\u308b\n\/\/\/ \n\/\/\/ [a] \u3068 [b] \u3092\u52a0\u7b97\u3057\u3066\u7d50\u679c\u3092\u8fd4\u3057\u307e\u3059\u3002\n\/\/\/ \n\/\/\/ Returns: \u52a0\u7b97\u7d50\u679c\n\/\/\/ \n\/\/\/ \u4f8b:\n\/\/\/ ```dart\n\/\/\/ int result = add(5, 3);  \/\/ 8\n\/\/\/ ```\nint add(int a, int b) {\n  return a + b;\n}\n\nvoid main() {\n  var user = User('\u592a\u90ce', 25);\n  user.introduce();\n  \n  print('\u5408\u8a08: ${add(10, 20)}');\n}\n<\/code><\/pre>\n\n\n\n
\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h3>\n\n\n\n
\/\/\/ \u826f\u3044\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3\u306e\u4f8b\n\/\/\/ \n\/\/\/ \u3053\u306e\u30af\u30e9\u30b9\u306f[User]\u60c5\u5831\u3092\u7ba1\u7406\u3057\u307e\u3059\u3002\n\/\/\/ \u8a73\u7d30\u306f\u516c\u5f0f\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u53c2\u7167: https:\/\/example.com\/docs\n\/\/\/ \n\/\/\/ **\u91cd\u8981:** \u5e74\u9f62\u306f\u5fc5\u305a0\u4ee5\u4e0a\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u3002\n\/\/\/ \n\/\/\/ \u4f7f\u7528\u53ef\u80fd\u306a\u30e1\u30bd\u30c3\u30c9:\n\/\/\/ * [updateAge] - \u5e74\u9f62\u3092\u66f4\u65b0\n\/\/\/ * [isAdult] - \u6210\u4eba\u304b\u3069\u3046\u304b\u3092\u5224\u5b9a\n\/\/\/ \n\/\/\/ See also:\n\/\/\/ * [Address] \u30af\u30e9\u30b9\n\/\/\/ * [Contact] \u30af\u30e9\u30b9\nclass UserProfile {\n  String name;\n  int age;\n  \n  UserProfile(this.name, this.age);\n  \n  \/\/\/ \u5e74\u9f62\u3092\u66f4\u65b0\u3059\u308b\n  \/\/\/ \n  \/\/\/ [newAge]\u306f0\u4ee5\u4e0a\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\n  \/\/\/ \n  \/\/\/ Throws:\n  \/\/\/ * [ArgumentError] \u5e74\u9f62\u304c\u8ca0\u306e\u5834\u5408\n  void updateAge(int newAge) {\n    if (newAge < 0) {\n      throw ArgumentError('\u5e74\u9f62\u306f0\u4ee5\u4e0a\u306b\u3057\u3066\u304f\u3060\u3055\u3044');\n    }\n    age = newAge;\n  }\n  \n  \/\/\/ \u6210\u4eba\uff0818\u6b73\u4ee5\u4e0a\uff09\u304b\u3069\u3046\u304b\u3092\u5224\u5b9a\n  \/\/\/ \n  \/\/\/ Returns: \u6210\u4eba\u306e\u5834\u5408true\u3001\u672a\u6210\u5e74\u306e\u5834\u5408false\n  bool isAdult() => age >= 18;\n}\n<\/code><\/pre>\n\n\n\n
\n\n\n\n
\u3053\u308c\u3067\u7b2c2\u7ae0\u300c\u57fa\u672c\u6587\u6cd5\u300d\u306e\u89e3\u8aac\u306f\u5b8c\u4e86\u3067\u3059\u3002\u3053\u308c\u3089\u306e\u57fa\u790e\u3092\u3057\u3063\u304b\u308a\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u8907\u96d1\u306aDart\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u66f8\u304f\u6e96\u5099\u304c\u6574\u3044\u307e\u3059\u3002\u6b21\u306e\u7ae0\u3067\u306f\u3001\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\uff08List\u3001Set\u3001Map\uff09\u306b\u3064\u3044\u3066\u5b66\u3093\u3067\u3044\u304d\u307e\u3057\u3087\u3046\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5909\u6570\u3068\u5b9a\u6570\uff08var, final, const\uff09 Dart\u3067\u306f\u3001\u30c7\u30fc\u30bf\u3092\u683c\u7d0d\u3059\u308b\u305f\u3081\u306b\u5909\u6570\u3068\u5b9a\u6570\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002 var – \u578b\u63a8\u8ad6\u306b\u3088\u308b\u5909\u6570\u5ba3\u8a00 \u660e\u793a\u7684\u306a\u578b\u5ba3\u8a00 final – \u5b9f\u884c\u6642\u306b\u4e00\u5ea6\u3060\u3051\u8a2d […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"saved_in_kubio":false,"footnotes":""},"categories":[70,67,4],"tags":[],"class_list":["post-3176","post","type-post","status-publish","format-standard","hentry","category-dart-flutter","category-flutter","category-tech"],"_links":{"self":[{"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/3176","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3176"}],"version-history":[{"count":1,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/3176\/revisions"}],"predecessor-version":[{"id":3177,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/3176\/revisions\/3177"}],"wp:attachment":[{"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3176"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3176"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}