List\u306f\u9806\u5e8f\u4ed8\u3051\u3089\u308c\u305f\u8981\u7d20\u306e\u96c6\u5408\u3067\u3059\u3002\u540c\u3058\u8981\u7d20\u3092\u8907\u6570\u56de\u542b\u3080\u3053\u3068\u304c\u3067\u304d\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3067\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n
void main() {\n \/\/ List\u306e\u4f5c\u6210\n List<int> numbers = [1, 2, 3, 4, 5];\n var fruits = ['\u308a\u3093\u3054', '\u30d0\u30ca\u30ca', '\u30aa\u30ec\u30f3\u30b8']; \/\/ \u578b\u63a8\u8ad6\n \n \/\/ \u7a7a\u306eList\n List<String> emptyList = [];\n var anotherEmpty = <String>[];\n \n \/\/ \u8981\u7d20\u3078\u306e\u30a2\u30af\u30bb\u30b9\n print('\u6700\u521d\u306e\u8981\u7d20: ${fruits[0]}'); \/\/ \u308a\u3093\u3054\n print('\u6700\u5f8c\u306e\u8981\u7d20: ${fruits[fruits.length - 1]}'); \/\/ \u30aa\u30ec\u30f3\u30b8\n print('\u6700\u5f8c\u306e\u8981\u7d20: ${fruits.last}'); \/\/ \u30aa\u30ec\u30f3\u30b8\n print('\u6700\u521d\u306e\u8981\u7d20: ${fruits.first}'); \/\/ \u308a\u3093\u3054\n \n \/\/ \u8981\u7d20\u6570\n print('\u8981\u7d20\u6570: ${fruits.length}');\n \n \/\/ \u7a7a\u304b\u3069\u3046\u304b\n print('\u7a7a?: ${fruits.isEmpty}'); \/\/ false\n print('\u7a7a\u3067\u306a\u3044?: ${fruits.isNotEmpty}'); \/\/ true\n}\n<\/code><\/pre>\n\n\n\nList\u3078\u306e\u8981\u7d20\u306e\u8ffd\u52a0\u30fb\u524a\u9664<\/h3>\n\n\n\nvoid main() {\n var fruits = ['\u308a\u3093\u3054', '\u30d0\u30ca\u30ca'];\n \n \/\/ \u672b\u5c3e\u306b\u8ffd\u52a0\n fruits.add('\u30aa\u30ec\u30f3\u30b8');\n print(fruits); \/\/ [\u308a\u3093\u3054, \u30d0\u30ca\u30ca, \u30aa\u30ec\u30f3\u30b8]\n \n \/\/ \u8907\u6570\u8981\u7d20\u3092\u8ffd\u52a0\n fruits.addAll(['\u3076\u3069\u3046', '\u3044\u3061\u3054']);\n print(fruits); \/\/ [\u308a\u3093\u3054, \u30d0\u30ca\u30ca, \u30aa\u30ec\u30f3\u30b8, \u3076\u3069\u3046, \u3044\u3061\u3054]\n \n \/\/ \u6307\u5b9a\u4f4d\u7f6e\u306b\u633f\u5165\n fruits.insert(1, '\u30e1\u30ed\u30f3');\n print(fruits); \/\/ [\u308a\u3093\u3054, \u30e1\u30ed\u30f3, \u30d0\u30ca\u30ca, \u30aa\u30ec\u30f3\u30b8, \u3076\u3069\u3046, \u3044\u3061\u3054]\n \n \/\/ \u6307\u5b9a\u4f4d\u7f6e\u306b\u8907\u6570\u633f\u5165\n fruits.insertAll(2, ['\u6843', '\u68a8']);\n print(fruits); \/\/ [\u308a\u3093\u3054, \u30e1\u30ed\u30f3, \u6843, \u68a8, \u30d0\u30ca\u30ca, \u30aa\u30ec\u30f3\u30b8, \u3076\u3069\u3046, \u3044\u3061\u3054]\n \n \/\/ \u8981\u7d20\u306e\u524a\u9664\n fruits.remove('\u30d0\u30ca\u30ca'); \/\/ \u6700\u521d\u306b\u898b\u3064\u304b\u3063\u305f\u8981\u7d20\u3092\u524a\u9664\n print(fruits);\n \n \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3067\u524a\u9664\n fruits.removeAt(0); \/\/ \u308a\u3093\u3054\u3092\u524a\u9664\n print(fruits);\n \n \/\/ \u6700\u5f8c\u306e\u8981\u7d20\u3092\u524a\u9664\n fruits.removeLast();\n print(fruits);\n \n \/\/ \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u3092\u524a\u9664\n fruits.removeWhere((fruit) => fruit.length > 3);\n print(fruits);\n \n \/\/ \u3059\u3079\u3066\u524a\u9664\n fruits.clear();\n print('\u30af\u30ea\u30a2\u5f8c: $fruits'); \/\/ []\n}\n<\/code><\/pre>\n\n\n\nList\u306e\u64cd\u4f5c<\/h3>\n\n\n\nvoid main() {\n var numbers = [5, 2, 8, 1, 9, 3];\n \n \/\/ \u30bd\u30fc\u30c8\n numbers.sort();\n print('\u6607\u9806: $numbers'); \/\/ [1, 2, 3, 5, 8, 9]\n \n numbers.sort((a, b) => b.compareTo(a)); \/\/ \u964d\u9806\n print('\u964d\u9806: $numbers'); \/\/ [9, 8, 5, 3, 2, 1]\n \n \/\/ \u53cd\u8ee2\n var reversed = numbers.reversed.toList();\n print('\u53cd\u8ee2: $reversed');\n \n \/\/ \u90e8\u5206\u30ea\u30b9\u30c8\n var sublist = numbers.sublist(1, 4); \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b91\u304b\u30893\u307e\u3067\n print('\u90e8\u5206\u30ea\u30b9\u30c8: $sublist');\n \n \/\/ \u8981\u7d20\u306e\u691c\u7d22\n print('5\u3092\u542b\u3080?: ${numbers.contains(5)}');\n print('5\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9: ${numbers.indexOf(5)}');\n print('10\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9: ${numbers.indexOf(10)}'); \/\/ -1\uff08\u898b\u3064\u304b\u3089\u306a\u3044\uff09\n \n \/\/ \u30ea\u30b9\u30c8\u306e\u7d50\u5408\n var list1 = [1, 2, 3];\n var list2 = [4, 5, 6];\n var combined = [...list1, ...list2];\n print('\u7d50\u5408: $combined');\n \n \/\/ \u7bc4\u56f2\u6307\u5b9a\n var range = List.generate(5, (index) => index * 2);\n print('\u751f\u6210: $range'); \/\/ [0, 2, 4, 6, 8]\n}\n<\/code><\/pre>\n\n\n\n\u56fa\u5b9a\u9577List\u3068\u6210\u9577\u53ef\u80fd\u306aList<\/h3>\n\n\n\nvoid main() {\n \/\/ \u6210\u9577\u53ef\u80fd\u306aList\uff08\u30c7\u30d5\u30a9\u30eb\u30c8\uff09\n var growable = [1, 2, 3];\n growable.add(4); \/\/ OK\n print('\u6210\u9577\u53ef\u80fd: $growable');\n \n \/\/ \u56fa\u5b9a\u9577List\n var fixed = List.filled(3, 0); \/\/ [0, 0, 0]\n print('\u56fa\u5b9a\u9577: $fixed');\n fixed[0] = 1; \/\/ \u8981\u7d20\u306e\u5909\u66f4\u306fOK\n \/\/ fixed.add(4); \/\/ \u30a8\u30e9\u30fc: \u56fa\u5b9a\u9577List\u306b\u306f\u8ffd\u52a0\u3067\u304d\u306a\u3044\n \n \/\/ \u56fa\u5b9a\u9577List\u3092\u6210\u9577\u53ef\u80fd\u306b\u5909\u63db\n var converted = fixed.toList(growable: true);\n converted.add(4); \/\/ OK\n print('\u5909\u63db\u5f8c: $converted');\n \n \/\/ \u5909\u66f4\u4e0d\u53ef\u80fd\u306aList\n var unmodifiable = List.unmodifiable([1, 2, 3]);\n \/\/ unmodifiable[0] = 5; \/\/ \u30a8\u30e9\u30fc: \u5909\u66f4\u4e0d\u53ef\n \/\/ unmodifiable.add(4); \/\/ \u30a8\u30e9\u30fc: \u8ffd\u52a0\u4e0d\u53ef\n}\n<\/code><\/pre>\n\n\n\nSet\uff08\u30bb\u30c3\u30c8\uff09<\/h2>\n\n\n\n
Set\u306f\u9806\u5e8f\u3092\u6301\u305f\u306a\u3044\u3001\u91cd\u8907\u306e\u306a\u3044\u8981\u7d20\u306e\u96c6\u5408\u3067\u3059\u3002<\/p>\n\n\n\n
Set\u306e\u57fa\u672c\u64cd\u4f5c<\/h3>\n\n\n\nvoid main() {\n \/\/ Set\u306e\u4f5c\u6210\n Set<int> numbers = {1, 2, 3, 4, 5};\n var fruits = {'\u308a\u3093\u3054', '\u30d0\u30ca\u30ca', '\u30aa\u30ec\u30f3\u30b8'};\n \n \/\/ \u91cd\u8907\u306f\u81ea\u52d5\u7684\u306b\u524a\u9664\u3055\u308c\u308b\n var duplicates = {1, 2, 2, 3, 3, 3};\n print('\u91cd\u8907\u524a\u9664: $duplicates'); \/\/ {1, 2, 3}\n \n \/\/ \u7a7a\u306eSet\n Set<String> emptySet = {};\n var anotherEmpty = <String>{};\n \n \/\/ \u8981\u7d20\u6570\n print('\u8981\u7d20\u6570: ${fruits.length}');\n \n \/\/ \u8981\u7d20\u306e\u5b58\u5728\u30c1\u30a7\u30c3\u30af\n print('\u308a\u3093\u3054\u3092\u542b\u3080?: ${fruits.contains('\u308a\u3093\u3054')}');\n \n \/\/ \u3059\u3079\u3066\u306e\u8981\u7d20\n print('\u3059\u3079\u3066\u306e\u8981\u7d20: $fruits');\n}\n<\/code><\/pre>\n\n\n\nSet\u3078\u306e\u8981\u7d20\u306e\u8ffd\u52a0\u30fb\u524a\u9664<\/h3>\n\n\n\nvoid main() {\n var fruits = {'\u308a\u3093\u3054', '\u30d0\u30ca\u30ca'};\n \n \/\/ \u8981\u7d20\u306e\u8ffd\u52a0\n fruits.add('\u30aa\u30ec\u30f3\u30b8');\n print(fruits);\n \n \/\/ \u91cd\u8907\u3057\u305f\u8981\u7d20\u3092\u8ffd\u52a0\u3057\u3088\u3046\u3068\u3057\u3066\u3082\u7121\u8996\u3055\u308c\u308b\n var added = fruits.add('\u308a\u3093\u3054');\n print('\u8ffd\u52a0\u6210\u529f?: $added'); \/\/ false\n print(fruits); \/\/ \u5909\u5316\u306a\u3057\n \n \/\/ \u8907\u6570\u8981\u7d20\u3092\u8ffd\u52a0\n fruits.addAll(['\u3076\u3069\u3046', '\u3044\u3061\u3054', '\u308a\u3093\u3054']);\n print(fruits); \/\/ \u308a\u3093\u3054\u306f\u91cd\u8907\u3057\u306a\u3044\u306e\u3067\u8ffd\u52a0\u3055\u308c\u306a\u3044\n \n \/\/ \u8981\u7d20\u306e\u524a\u9664\n fruits.remove('\u30d0\u30ca\u30ca');\n print(fruits);\n \n \/\/ \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u3092\u524a\u9664\n fruits.removeWhere((fruit) => fruit.length > 4);\n print(fruits);\n \n \/\/ \u3059\u3079\u3066\u524a\u9664\n fruits.clear();\n print('\u30af\u30ea\u30a2\u5f8c: $fruits');\n}\n<\/code><\/pre>\n\n\n\nSet\u6f14\u7b97<\/h3>\n\n\n\nvoid main() {\n var set1 = {1, 2, 3, 4, 5};\n var set2 = {4, 5, 6, 7, 8};\n \n \/\/ \u548c\u96c6\u5408\uff08union\uff09\n var union = set1.union(set2);\n print('\u548c\u96c6\u5408: $union'); \/\/ {1, 2, 3, 4, 5, 6, 7, 8}\n \n \/\/ \u7a4d\u96c6\u5408\uff08intersection\uff09\n var intersection = set1.intersection(set2);\n print('\u7a4d\u96c6\u5408: $intersection'); \/\/ {4, 5}\n \n \/\/ \u5dee\u96c6\u5408\uff08difference\uff09\n var difference = set1.difference(set2);\n print('\u5dee\u96c6\u5408: $difference'); \/\/ {1, 2, 3}\n \n \/\/ \u90e8\u5206\u96c6\u5408\u304b\u3069\u3046\u304b\n var subset = {1, 2};\n print('\u90e8\u5206\u96c6\u5408?: ${subset.difference(set1).isEmpty}'); \/\/ true\n \n \/\/ List\u304b\u3089\u91cd\u8907\u3092\u524a\u9664\n var listWithDuplicates = [1, 2, 2, 3, 3, 3, 4, 5, 5];\n var uniqueSet = listWithDuplicates.toSet();\n print('\u91cd\u8907\u524a\u9664: $uniqueSet'); \/\/ {1, 2, 3, 4, 5}\n \n \/\/ Set\u3092List\u306b\u5909\u63db\n var backToList = uniqueSet.toList();\n print('List\u5316: $backToList');\n}\n<\/code><\/pre>\n\n\n\nMap\uff08\u30de\u30c3\u30d7\uff09<\/h2>\n\n\n\n
Map\u306f\u30ad\u30fc\u3068\u5024\u306e\u30da\u30a2\u3092\u683c\u7d0d\u3059\u308b\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u3067\u3059\u3002\u4ed6\u306e\u8a00\u8a9e\u3067\u306f\u8f9e\u66f8\uff08Dictionary\uff09\u3084\u30cf\u30c3\u30b7\u30e5\u30de\u30c3\u30d7\u3068\u547c\u3070\u308c\u307e\u3059\u3002<\/p>\n\n\n\n
Map\u306e\u57fa\u672c\u64cd\u4f5c<\/h3>\n\n\n\nvoid main() {\n \/\/ Map\u306e\u4f5c\u6210\n Map<String, int> scores = {\n '\u592a\u90ce': 85,\n '\u82b1\u5b50': 92,\n '\u6b21\u90ce': 78\n };\n \n \/\/ \u578b\u63a8\u8ad6\n var capitals = {\n '\u65e5\u672c': '\u6771\u4eac',\n '\u30a2\u30e1\u30ea\u30ab': '\u30ef\u30b7\u30f3\u30c8\u30f3D.C.',\n '\u30d5\u30e9\u30f3\u30b9': '\u30d1\u30ea'\n };\n \n \/\/ \u7a7a\u306eMap\n Map<String, String> emptyMap = {};\n var anotherEmpty = <String, int>{};\n \n \/\/ \u5024\u3078\u306e\u30a2\u30af\u30bb\u30b9\n print('\u592a\u90ce\u306e\u70b9\u6570: ${scores['\u592a\u90ce']}');\n print('\u65e5\u672c\u306e\u9996\u90fd: ${capitals['\u65e5\u672c']}');\n \n \/\/ \u5b58\u5728\u3057\u306a\u3044\u30ad\u30fc\u306fnull\u3092\u8fd4\u3059\n print('\u4e09\u90ce\u306e\u70b9\u6570: ${scores['\u4e09\u90ce']}'); \/\/ null\n \n \/\/ \u30ad\u30fc\u306e\u5b58\u5728\u30c1\u30a7\u30c3\u30af\n print('\u592a\u90ce\u304c\u5b58\u5728?: ${scores.containsKey('\u592a\u90ce')}');\n print('\u502492\u304c\u5b58\u5728?: ${scores.containsValue(92)}');\n \n \/\/ \u8981\u7d20\u6570\n print('\u8981\u7d20\u6570: ${scores.length}');\n \n \/\/ \u3059\u3079\u3066\u306e\u30ad\u30fc\n print('\u30ad\u30fc: ${scores.keys}');\n \n \/\/ \u3059\u3079\u3066\u306e\u5024\n print('\u5024: ${scores.values}');\n}\n<\/code><\/pre>\n\n\n\nMap\u3078\u306e\u8981\u7d20\u306e\u8ffd\u52a0\u30fb\u66f4\u65b0\u30fb\u524a\u9664<\/h3>\n\n\n\nvoid main() {\n var scores = {'\u592a\u90ce': 85, '\u82b1\u5b50': 92};\n \n \/\/ \u8981\u7d20\u306e\u8ffd\u52a0\n scores['\u6b21\u90ce'] = 78;\n print(scores);\n \n \/\/ \u8981\u7d20\u306e\u66f4\u65b0\n scores['\u592a\u90ce'] = 90;\n print(scores);\n \n \/\/ \u8907\u6570\u8981\u7d20\u3092\u8ffd\u52a0\n scores.addAll({\n '\u56db\u90ce': 88,\n '\u4e94\u90ce': 95\n });\n print(scores);\n \n \/\/ \u30ad\u30fc\u304c\u5b58\u5728\u3057\u306a\u3044\u5834\u5408\u306e\u307f\u8ffd\u52a0\n scores.putIfAbsent('\u592a\u90ce', () => 100); \/\/ \u65e2\u306b\u5b58\u5728\u3059\u308b\u306e\u3067\u8ffd\u52a0\u3055\u308c\u306a\u3044\n scores.putIfAbsent('\u516d\u90ce', () => 80); \/\/ \u8ffd\u52a0\u3055\u308c\u308b\n print(scores);\n \n \/\/ \u8981\u7d20\u306e\u524a\u9664\n scores.remove('\u6b21\u90ce');\n print(scores);\n \n \/\/ \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u3092\u524a\u9664\n scores.removeWhere((key, value) => value < 85);\n print(scores);\n \n \/\/ \u3059\u3079\u3066\u524a\u9664\n scores.clear();\n print('\u30af\u30ea\u30a2\u5f8c: $scores');\n}\n<\/code><\/pre>\n\n\n\nMap\u306e\u64cd\u4f5c<\/h3>\n\n\n\nvoid main() {\n var scores = {\n '\u592a\u90ce': 85,\n '\u82b1\u5b50': 92,\n '\u6b21\u90ce': 78,\n '\u56db\u90ce': 95\n };\n \n \/\/ \u3059\u3079\u3066\u306e\u30a8\u30f3\u30c8\u30ea\u3092\u51e6\u7406\n scores.forEach((name, score) {\n print('$name: $score\u70b9');\n });\n \n \/\/ \u30ad\u30fc\u3067\u30bd\u30fc\u30c8\n var sortedKeys = scores.keys.toList()..sort();\n print('\\n\u30ad\u30fc\u3067\u30bd\u30fc\u30c8:');\n for (var key in sortedKeys) {\n print('$key: ${scores[key]}');\n }\n \n \/\/ \u5024\u3067\u30bd\u30fc\u30c8\n var sortedEntries = scores.entries.toList()\n ..sort((a, b) => b.value.compareTo(a.value));\n print('\\n\u5024\u3067\u30bd\u30fc\u30c8\uff08\u964d\u9806\uff09:');\n for (var entry in sortedEntries) {\n print('${entry.key}: ${entry.value}');\n }\n \n \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u3092\u4f7f\u3063\u305f\u30a2\u30af\u30bb\u30b9\n print('\\n\u4e94\u90ce\u306e\u70b9\u6570: ${scores['\u4e94\u90ce'] ?? 0}'); \/\/ \u5b58\u5728\u3057\u306a\u3044\u306e\u30670\n \n \/\/ Map\u306e\u5909\u63db\n var doubled = scores.map((key, value) => MapEntry(key, value * 2));\n print('\\n2\u500d: $doubled');\n}\n<\/code><\/pre>\n\n\n\n\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u64cd\u4f5c\u3068\u30e1\u30bd\u30c3\u30c9<\/h2>\n\n\n\n\u95a2\u6570\u578b\u30e1\u30bd\u30c3\u30c9<\/h3>\n\n\n\nvoid main() {\n var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];\n \n \/\/ map - \u5404\u8981\u7d20\u3092\u5909\u63db\n var squared = numbers.map((n) => n * n).toList();\n print('2\u4e57: $squared');\n \n \/\/ where - \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u3092\u30d5\u30a3\u30eb\u30bf\u30ea\u30f3\u30b0\n var evens = numbers.where((n) => n % 2 == 0).toList();\n print('\u5076\u6570: $evens');\n \n \/\/ firstWhere - \u6761\u4ef6\u306b\u5408\u3046\u6700\u521d\u306e\u8981\u7d20\n var firstEven = numbers.firstWhere((n) => n % 2 == 0);\n print('\u6700\u521d\u306e\u5076\u6570: $firstEven');\n \n \/\/ firstWhere\uff08\u898b\u3064\u304b\u3089\u306a\u3044\u5834\u5408\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\uff09\n var bigNumber = numbers.firstWhere(\n (n) => n > 100,\n orElse: () => -1\n );\n print('100\u3088\u308a\u5927\u304d\u3044\u6570: $bigNumber'); \/\/ -1\n \n \/\/ lastWhere - \u6761\u4ef6\u306b\u5408\u3046\u6700\u5f8c\u306e\u8981\u7d20\n var lastEven = numbers.lastWhere((n) => n % 2 == 0);\n print('\u6700\u5f8c\u306e\u5076\u6570: $lastEven');\n \n \/\/ any - \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u304c1\u3064\u3067\u3082\u3042\u308b\u304b\n var hasEven = numbers.any((n) => n % 2 == 0);\n print('\u5076\u6570\u304c\u542b\u307e\u308c\u308b?: $hasEven');\n \n \/\/ every - \u3059\u3079\u3066\u306e\u8981\u7d20\u304c\u6761\u4ef6\u306b\u5408\u3046\u304b\n var allPositive = numbers.every((n) => n > 0);\n print('\u3059\u3079\u3066\u6b63\u6570?: $allPositive');\n \n \/\/ skip - \u6700\u521d\u306eN\u500b\u3092\u30b9\u30ad\u30c3\u30d7\n var skipped = numbers.skip(3).toList();\n print('\u6700\u521d\u306e3\u500b\u3092\u30b9\u30ad\u30c3\u30d7: $skipped');\n \n \/\/ take - \u6700\u521d\u306eN\u500b\u3092\u53d6\u5f97\n var taken = numbers.take(5).toList();\n print('\u6700\u521d\u306e5\u500b: $taken');\n \n \/\/ reduce - \u7d2f\u7a4d\u51e6\u7406\n var sum = numbers.reduce((a, b) => a + b);\n print('\u5408\u8a08: $sum');\n \n \/\/ fold - \u521d\u671f\u5024\u3092\u6307\u5b9a\u3057\u305f\u7d2f\u7a4d\u51e6\u7406\n var product = numbers.fold(1, (prev, element) => prev * element);\n print('\u7a4d: $product');\n}\n<\/code><\/pre>\n\n\n\n\u3088\u308a\u9ad8\u5ea6\u306a\u64cd\u4f5c<\/h3>\n\n\n\nvoid main() {\n var students = [\n {'name': '\u592a\u90ce', 'score': 85},\n {'name': '\u82b1\u5b50', 'score': 92},\n {'name': '\u6b21\u90ce', 'score': 78},\n {'name': '\u56db\u90ce', 'score': 95},\n {'name': '\u4e94\u90ce', 'score': 88}\n ];\n \n \/\/ \u6761\u4ef6\u306b\u5408\u3046\u8981\u7d20\u306e\u6570\n var highScorers = students.where((s) => s['score']! as int > 85).length;\n print('85\u70b9\u4ee5\u4e0a\u306e\u4eba\u6570: $highScorers');\n \n \/\/ \u6700\u5927\u5024\n var maxScore = students.map((s) => s['score'] as int).reduce((a, b) => a > b ? a : b);\n print('\u6700\u9ad8\u70b9: $maxScore');\n \n \/\/ \u5e73\u5747\u5024\n var total = students.fold(0, (sum, s) => sum + (s['score'] as int));\n var average = total \/ students.length;\n print('\u5e73\u5747\u70b9: ${average.toStringAsFixed(1)}');\n \n \/\/ \u30b0\u30eb\u30fc\u30d7\u5316\uff08\u624b\u52d5\u5b9f\u88c5\uff09\n var grouped = <String, List<Map<String, Object>>>{};\n for (var student in students) {\n var score = student['score'] as int;\n var grade = score >= 90 ? 'A' : score >= 80 ? 'B' : 'C';\n grouped.putIfAbsent(grade, () => []).add(student);\n }\n print('\\n\u6210\u7e3e\u5225\u30b0\u30eb\u30fc\u30d7:');\n grouped.forEach((grade, studentList) {\n print('$grade: ${studentList.map((s) => s['name']).join(', ')}');\n });\n \n \/\/ \u8907\u6570\u306e\u64cd\u4f5c\u3092\u9023\u9396\n var topThreeNames = students\n .where((s) => s['score']! as int >= 85)\n .map((s) => s['name'] as String)\n .take(3)\n .toList();\n print('\\n\u4e0a\u4f4d3\u540d: $topThreeNames');\n}\n<\/code><\/pre>\n\n\n\n\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306e\u30b3\u30d4\u30fc<\/h3>\n\n\n\nvoid main() {\n var original = [1, 2, 3];\n \n \/\/ \u6d45\u3044\u30b3\u30d4\u30fc\n var shallowCopy = [...original];\n shallowCopy[0] = 999;\n print('\u5143\u306e\u30ea\u30b9\u30c8: $original'); \/\/ [1, 2, 3]\n print('\u30b3\u30d4\u30fc: $shallowCopy'); \/\/ [999, 2, 3]\n \n \/\/ \u30cd\u30b9\u30c8\u3055\u308c\u305f\u30ea\u30b9\u30c8\u306e\u5834\u5408\n var nested = [[1, 2], [3, 4]];\n var nestedCopy = [...nested];\n nestedCopy[0][0] = 999; \/\/ \u5185\u5074\u306e\u30ea\u30b9\u30c8\u306f\u5171\u6709\u3055\u308c\u308b\n print('\u5143\u306e\u30cd\u30b9\u30c8\u30ea\u30b9\u30c8: $nested'); \/\/ [[999, 2], [3, 4]]\n print('\u30b3\u30d4\u30fc: $nestedCopy'); \/\/ [[999, 2], [3, 4]]\n \n \/\/ \u6df1\u3044\u30b3\u30d4\u30fc\uff08\u624b\u52d5\uff09\n var deepCopy = nested.map((list) => [...list]).toList();\n deepCopy[0][0] = 111;\n print('\u5143\u306e\u30cd\u30b9\u30c8\u30ea\u30b9\u30c8: $nested'); \/\/ [[999, 2], [3, 4]]\n print('\u6df1\u3044\u30b3\u30d4\u30fc: $deepCopy'); \/\/ [[111, 2], [3, 4]]\n}\n<\/code><\/pre>\n\n\n\nSpread\u6f14\u7b97\u5b50\u3068Collection if\/for<\/h2>\n\n\n\nSpread\u6f14\u7b97\u5b50\uff08…\uff09<\/h3>\n\n\n\nvoid main() {\n \/\/ \u30ea\u30b9\u30c8\u306e\u5c55\u958b\n var list1 = [1, 2, 3];\n var list2 = [4, 5, 6];\n var combined = [...list1, ...list2];\n print('\u7d50\u5408: $combined'); \/\/ [1, 2, 3, 4, 5, 6]\n \n \/\/ \u9014\u4e2d\u306b\u8981\u7d20\u3092\u631f\u3080\n var mixed = [...list1, 99, ...list2];\n print('\u6df7\u5408: $mixed'); \/\/ [1, 2, 3, 99, 4, 5, 6]\n \n \/\/ null\u30bb\u30fc\u30d5\u306aSpread\u6f14\u7b97\u5b50\uff08...?\uff09\n List<int>? nullableList;\n var safe = [1, 2, ...?nullableList, 3];\n print('null\u30bb\u30fc\u30d5: $safe'); \/\/ [1, 2, 3]\n \n nullableList = [10, 20];\n safe = [1, 2, ...?nullableList, 3];\n print('null\u30bb\u30fc\u30d5: $safe'); \/\/ [1, 2, 10, 20, 3]\n \n \/\/ Set\u3067\u306e\u4f7f\u7528\n var set1 = {1, 2, 3};\n var set2 = {3, 4, 5};\n var combinedSet = {...set1, ...set2};\n print('Set\u7d50\u5408: $combinedSet'); \/\/ {1, 2, 3, 4, 5}\n \n \/\/ Map\u3067\u306e\u4f7f\u7528\n var map1 = {'a': 1, 'b': 2};\n var map2 = {'c': 3, 'd': 4};\n var combinedMap = {...map1, ...map2};\n print('Map\u7d50\u5408: $combinedMap');\n \n \/\/ \u5024\u306e\u4e0a\u66f8\u304d\n var overwritten = {...map1, 'b': 99, ...map2};\n print('\u4e0a\u66f8\u304d: $overwritten'); \/\/ {a: 1, b: 99, c: 3, d: 4}\n}\n<\/code><\/pre>\n\n\n\nCollection if<\/h3>\n\n\n\nvoid main() {\n bool includeZero = true;\n var numbers = [\n if (includeZero) 0,\n 1,\n 2,\n 3\n ];\n print('0\u3092\u542b\u3080: $numbers');\n \n includeZero = false;\n numbers = [\n if (includeZero) 0,\n 1,\n 2,\n 3\n ];\n print('0\u3092\u542b\u307e\u306a\u3044: $numbers');\n \n \/\/ if-else\n bool isEven = true;\n var list = [\n 1,\n if (isEven) 2 else 3,\n 4\n ];\n print('\u6761\u4ef6\u5206\u5c90: $list');\n \n \/\/ \u8907\u6570\u8981\u7d20\u306e\u6761\u4ef6\u4ed8\u304d\u8ffd\u52a0\n bool includeExtras = true;\n var items = [\n '\u308a\u3093\u3054',\n '\u30d0\u30ca\u30ca',\n if (includeExtras) ...[\n '\u30aa\u30ec\u30f3\u30b8',\n '\u3076\u3069\u3046',\n '\u3044\u3061\u3054'\n ]\n ];\n print('\u30a2\u30a4\u30c6\u30e0: $items');\n \n \/\/ Set\u3067\u306e\u4f7f\u7528\n var roles = {\n 'user',\n if (true) 'admin',\n if (false) 'superadmin'\n };\n print('\u5f79\u5272: $roles');\n \n \/\/ Map\u3067\u306e\u4f7f\u7528\n var config = {\n 'name': 'MyApp',\n 'version': '1.0',\n if (true) 'debug': true,\n if (false) 'test': true\n };\n print('\u8a2d\u5b9a: $config');\n}\n<\/code><\/pre>\n\n\n\nCollection for<\/h3>\n\n\n\nvoid main() {\n \/\/ \u57fa\u672c\u7684\u306a\u4f7f\u7528\n var numbers = [\n for (var i = 1; i <= 5; i++) i\n ];\n print('1-5: $numbers');\n \n \/\/ \u5909\u63db\u3057\u306a\u304c\u3089\u751f\u6210\n var squared = [\n for (var i = 1; i <= 5; i++) i * i\n ];\n print('2\u4e57: $squared');\n \n \/\/ \u65e2\u5b58\u306e\u30ea\u30b9\u30c8\u304b\u3089\u751f\u6210\n var fruits = ['\u308a\u3093\u3054', '\u30d0\u30ca\u30ca', '\u30aa\u30ec\u30f3\u30b8'];\n var upperFruits = [\n for (var fruit in fruits) fruit.toUpperCase()\n ];\n print('\u5927\u6587\u5b57: $upperFruits');\n \n \/\/ \u6761\u4ef6\u4ed8\u304d\u3067\u751f\u6210\n var evenNumbers = [\n for (var i = 1; i <= 10; i++)\n if (i % 2 == 0) i\n ];\n print('\u5076\u6570: $evenNumbers');\n \n \/\/ \u30cd\u30b9\u30c8\u3057\u305f\u30eb\u30fc\u30d7\n var pairs = [\n for (var i = 1; i <= 3; i++)\n for (var j = 1; j <= 3; j++)\n '($i, $j)'\n ];\n print('\u30da\u30a2: $pairs');\n \n \/\/ Set\u3067\u306e\u4f7f\u7528\n var uniqueSquares = {\n for (var i = 1; i <= 5; i++) i * i\n };\n print('\u91cd\u8907\u306a\u30572\u4e57: $uniqueSquares');\n \n \/\/ Map\u3067\u306e\u4f7f\u7528\n var numberMap = {\n for (var i = 1; i <= 5; i++) i: i * i\n };\n print('\u6570\u5024\u30de\u30c3\u30d7: $numberMap');\n}\n<\/code><\/pre>\n\n\n\nCollection if\/for\u306e\u7d44\u307f\u5408\u308f\u305b<\/h3>\n\n\n\nvoid main() {\n \/\/ \u8907\u96d1\u306a\u6761\u4ef6\u3067\u306e\u751f\u6210\n var products = [\n {'name': '\u308a\u3093\u3054', 'price': 100},\n {'name': '\u30d0\u30ca\u30ca', 'price': 150},\n {'name': '\u30aa\u30ec\u30f3\u30b8', 'price': 200},\n ];\n \n bool showExpensive = true;\n int minPrice = 120;\n \n var displayList = [\n for (var product in products)\n if (!showExpensive || product['price']! as int >= minPrice)\n '${product['name']}: ${product['price']}\u5186'\n ];\n print('\u8868\u793a\u30ea\u30b9\u30c8: $displayList');\n \n \/\/ \u30b0\u30ea\u30c3\u30c9\u306e\u751f\u6210\n var grid = [\n for (var row = 0; row < 3; row++)\n [\n for (var col = 0; col < 3; col++)\n row * 3 + col\n ]\n ];\n print('\u30b0\u30ea\u30c3\u30c9:');\n for (var row in grid) {\n print(row);\n }\n \n \/\/ \u8907\u96d1\u306aMap\u751f\u6210\n var students = ['\u592a\u90ce', '\u82b1\u5b50', '\u6b21\u90ce'];\n var initialScores = {\n for (var i = 0; i < students.length; i++)\n students[i]: i * 10 + 70\n };\n print('\u521d\u671f\u30b9\u30b3\u30a2: $initialScores');\n \n \/\/ \u6761\u4ef6\u4ed8\u304dMap\u751f\u6210\n var config = {\n 'appName': 'MyApp',\n for (var env in ['dev', 'prod'])\n if (env == 'dev')\n 'debug': true\n else\n 'optimize': true\n };\n print('\u8a2d\u5b9a: $config');\n}\n<\/code><\/pre>\n\n\n\n\u5b9f\u8df5\u7684\u306a\u4f8b<\/h3>\n\n\n\nvoid main() {\n \/\/ \u30e6\u30fc\u30b6\u30fc\u30ea\u30b9\u30c8\u306e\u751f\u6210\n var userIds = [1, 2, 3, 4, 5];\n var includeAdmin = true;\n \n var users = [\n if (includeAdmin) {'id': 0, 'name': 'Admin', 'role': 'admin'},\n for (var id in userIds)\n if (id % 2 == 1)\n {'id': id, 'name': 'User$id', 'role': 'user'}\n ];\n \n print('\u30e6\u30fc\u30b6\u30fc\u4e00\u89a7:');\n for (var user in users) {\n print(' ${user['name']} (${user['role']})');\n }\n \n \/\/ \u52d5\u7684\u306a\u30e1\u30cb\u30e5\u30fc\u751f\u6210\n bool isLoggedIn = true;\n bool isAdmin = false;\n \n var menuItems = [\n '\u30db\u30fc\u30e0',\n if (isLoggedIn) ...[\n '\u30de\u30a4\u30da\u30fc\u30b8',\n '\u8a2d\u5b9a',\n if (isAdmin) '\u7ba1\u7406\u753b\u9762'\n ] else ...[\n '\u30ed\u30b0\u30a4\u30f3',\n '\u65b0\u898f\u767b\u9332'\n ]\n ];\n \n print('\\n\u30e1\u30cb\u30e5\u30fc:');\n for (var item in menuItems) {\n print(' - $item');\n }\n \n \/\/ \u30c7\u30fc\u30bf\u306e\u6574\u5f62\n var rawData = [\n [1, 2, 3],\n null,\n [4, 5, 6],\n [],\n [7, 8, 9]\n ];\n \n var cleanedData = [\n for (var item in rawData)\n if (item != null && item.isNotEmpty)\n ...item\n ];\n \n print('\\n\u6574\u5f62\u5f8c\u30c7\u30fc\u30bf: $cleanedData');\n}\n<\/code><\/pre>\n\n\n\n
\n\n\n\n\u3053\u308c\u3067\u7b2c3\u7ae0\u300c\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u300d\u306e\u89e3\u8aac\u306f\u5b8c\u4e86\u3067\u3059\u3002List\u3001Set\u3001Map\u306e\u57fa\u672c\u64cd\u4f5c\u304b\u3089\u3001\u9ad8\u5ea6\u306a\u95a2\u6570\u578b\u30e1\u30bd\u30c3\u30c9\u3001\u305d\u3057\u3066Spread\u6f14\u7b97\u5b50\u3084Collection if\/for\u3068\u3044\u3063\u305f\u73fe\u4ee3\u7684\u306a\u6a5f\u80fd\u307e\u3067\u5b66\u3073\u307e\u3057\u305f\u3002\u3053\u308c\u3089\u306e\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u64cd\u4f5c\u3092\u4f7f\u3044\u3053\u306a\u3059\u3053\u3068\u3067\u3001\u3088\u308a\u52b9\u7387\u7684\u3067\u8aad\u307f\u3084\u3059\u3044\u30b3\u30fc\u30c9\u304c\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u7ae0\u3067\u306f\u3001Dart\u306e\u30af\u30e9\u30b9\u3068\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306b\u3064\u3044\u3066\u5b66\u3093\u3067\u3044\u304d\u307e\u3057\u3087\u3046\uff01<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
List\uff08\u30ea\u30b9\u30c8\uff09 List\u306f\u9806\u5e8f\u4ed8\u3051\u3089\u308c\u305f\u8981\u7d20\u306e\u96c6\u5408\u3067\u3059\u3002\u540c\u3058\u8981\u7d20\u3092\u8907\u6570\u56de\u542b\u3080\u3053\u3068\u304c\u3067\u304d\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3067\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002 List\u306e\u57fa\u672c\u64cd\u4f5c List\u3078\u306e\u8981\u7d20\u306e\u8ffd\u52a0\u30fb\u524a\u9664 List\u306e\u64cd\u4f5c \u56fa\u5b9a\u9577List\u3068\u6210\u9577\u53ef\u80fd\u306aL […]<\/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-3178","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\/3178","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=3178"}],"version-history":[{"count":1,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/3178\/revisions"}],"predecessor-version":[{"id":3179,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/3178\/revisions\/3179"}],"wp:attachment":[{"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3178"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3178"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.blowfish.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3178"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}