{"id":203,"date":"2023-05-24T10:53:36","date_gmt":"2023-05-24T02:53:36","guid":{"rendered":"https:\/\/www.escook.cn\/?p=203"},"modified":"2023-09-26T21:06:56","modified_gmt":"2023-09-26T13:06:56","slug":"dart-%e5%9f%ba%e7%a1%80-%e5%86%85%e7%bd%ae%e7%b1%bb%e5%9e%8b-set-%e9%9b%86%e5%90%88","status":"publish","type":"post","link":"https:\/\/www.escook.cn\/index.php\/2023\/05\/24\/dart-%e5%9f%ba%e7%a1%80-%e5%86%85%e7%bd%ae%e7%b1%bb%e5%9e%8b-set-%e9%9b%86%e5%90%88\/","title":{"rendered":"Dart \u57fa\u7840 \u2013 \u5185\u7f6e\u7c7b\u578b \u2013 Set \u96c6\u5408"},"content":{"rendered":"
\n

\u7248\u6743\u5f52\u4f5c\u8005 \u00a9\u5218\u9f99\u5bbe<\/strong> \u6240\u6709\uff0c\u672c\u6587\u7ae0\u672a\u7ecf\u4f5c\u8005\u5141\u8bb8\uff0c\u7981\u6b62\u79c1\u81ea\u8f6c\u8f7d\uff01<\/p>\n<\/blockquote>\n

\u5728 Dart \u4e2d\uff0cSet<\/code> \u662f\u4e00\u4e2a\u65e0\u5e8f<\/strong>\u7684\u3001\u5143\u7d20\u552f\u4e00<\/strong>\u7684\u96c6\u5408\u3002<\/p>\n

\u7531\u4e8e Set \u662f\u65e0\u5e8f\u7684\uff0c\u6240\u4ee5\u65e0\u6cd5<\/strong>\u50cf List<\/code> \u6570\u7ec4\u90a3\u6837\u901a\u8fc7\u7d22\u5f15<\/strong>\uff08\u4e0b\u6807\uff09\u83b7\u53d6 Set \u4e2d\u7684\u5143\u7d20\u3002<\/p>\n

1. \u521b\u5efa Set \u96c6\u5408<\/h2>\n

1.1 \u57fa\u4e8e\u5b57\u9762\u91cf\u521b\u5efa Set<\/h3>\n
\n

\u6e29\u99a8\u63d0\u793a\uff1a\u5c3d\u7ba1 Set \u7c7b\u578b(type)<\/strong> \u4e00\u76f4\u90fd\u662f Dart \u7684\u4e00\u9879\u6838\u5fc3\u529f\u80fd\uff0c\u4f46\u662f Set \u5b57\u9762\u91cf(literals)<\/strong> \u662f\u5728 Dart 2.2 \u4e2d\u624d\u52a0\u5165\u7684\u3002<\/p>\n<\/blockquote>\n

1.1.1 \u5f3a\u7c7b\u578b\u7684 Set<\/h4>\n

\u58f0\u660e Set \u5b57\u9762\u91cf\u7684\u8bed\u6cd5\u662f <\u7c7b\u578b>{}<\/code>\u3002\u8fd9\u91cc\u9700\u8981\u7279\u522b\u63d0\u9192\u4e0b\uff0c\u5de6\u4fa7\u7684 <\u7c7b\u578b><\/code> \u662f\u5fc5\u987b\u7684\uff0c\u5982\u679c\u7701\u7565\u4e86\u7c7b\u578b\uff0c\u53ea\u5199\u4e86 {}<\/code>\uff0c\u90a3\u4e48\u4f1a\u88ab Dart \u7f16\u8bd1\u6210 Map \u7684\u5b57\u9762\u91cf\u3002\u4e0b\u9762\u7684\u4ee3\u7801\u6f14\u793a\u4e86\u5982\u4f55\u58f0\u660e Set \u5b57\u9762\u91cf\uff1a<\/p>\n

void main(List<String> args) {\n  \/\/ 1. \u58f0\u660e\u5b57\u7b26\u4e32\u7c7b\u578b\u7684 Set \u96c6\u5408\n  var names = <String>{'liulongbin', 'escook'};\n\n  \/\/ 2. \u5411 Set \u4e2d\u6dfb\u52a0\u91cd\u590d\u7684\u5143\u7d20\n  names.add('liulongbin');\n\n  \/\/ 3. \u7531\u4e8e Set \u4e2d\u7684\u5143\u7d20\u5177\u6709\u552f\u4e00\u6027\uff0c\u6240\u4ee5\u91cd\u590d\u6dfb\u52a0\u7684\u5143\u7d20\u4f1a\u88ab\u5c4f\u853d\n  \/\/ \u8f93\u51fa {liulongbin, escook}\n  print(names);\n}<\/code><\/pre>\n
1.1.2 dynamic \u7684 Set<\/h4>\n
\u5f3a\u7c7b\u578b<\/strong>\u7684 Set \u53ea\u80fd\u6dfb\u52a0\u7c7b\u578b\u76f8\u540c\u7684\u5143\u7d20<\/strong>\uff0c\u5982\u679c\u60f3\u521b\u5efa dynamic \u7c7b\u578b\u7684 Set\uff0c\u63a8\u8350\u4f7f\u7528 <dynamic>{}<\/code> \u7684\u65b9\u5f0f\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u521b\u5efa\u52a8\u6001\u7c7b\u578b\u7684 Set\uff0c\u53ef\u4ee5\u5411\u96c6\u5408\u4e2d\u63d2\u5165\u4efb\u4f55\u7c7b\u578b\u7684\u5143\u7d20\n  var names = <dynamic>{'liulongbin', 666};\n\n  \/\/ 2. \u8f93\u51fa {liulongbin, 666}\n  print(names);\n}<\/code><\/pre>\n
1.2 \u57fa\u4e8e\u6784\u9020\u51fd\u6570\u521b\u5efa Set<\/h3>\n
1.2.1 Set<\u7c7b\u578b>.identity()<\/h4>\n
Set \u96c6\u5408\u7684 identity<\/code> \u6784\u9020\u51fd\u6570\uff0c\u7528\u6765\u521b\u5efa\u7a7a\u767d\u7684 Set \u96c6\u5408<\/strong>\u3002\u5982\u679c\u6307\u5b9a\u4e86\u7c7b\u578b\uff0c\u5219\u662f\u5f3a\u7c7b\u578b<\/strong>\u7684 Set\uff1b\u5982\u679c\u7701\u7565\u4e86 <\u7c7b\u578b><\/code> \u6216\u63d0\u4f9b\u7684\u7c7b\u578b\u662f <dynamic><\/code>\uff0c\u5219\u521b\u5efa\u7684\u662f\u52a8\u6001\u7c7b\u578b<\/strong>\u7684 Set\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1.1 \u521b\u5efa String \u5f3a\u7c7b\u578b\u7684\u7a7a Set\n  var names = Set<String>.identity();\n\n  \/\/ 1.2 \u6dfb\u52a0\u5143\u7d20\n  names.add('liulongbin');\n  names.add('escook');\n\n  \/\/ 1.3 \u8f93\u51fa {liulongbin, escook}\n  print(names);\n\n  \/\/ ----\n\n  \/\/ 2.1 \u521b\u5efa\u52a8\u6001\u7c7b\u578b\u7684 Set\n  var sets = Set<dynamic>.identity();\n\n  \/\/ 2.2 \u6dfb\u52a0\u5b57\u7b26\u4e32\u3001\u6570\u5b57\u3001\u5e03\u5c14\u5143\u7d20\n  sets.add('liulongbin');\n  sets.add(666);\n  sets.add(true);\n\n  \/\/ 2.3 \u8f93\u51fa {liulongbin, 666, true}\n  print(sets);\n}<\/code><\/pre>\n
1.2.2 Set<\u7c7b\u578b>.from(\u53ef\u8fed\u4ee3\u7684\u96c6\u5408)<\/h4>\n
\u8c03\u7528 from<\/code> \u6784\u9020\u51fd\u6570\uff0c\u53ef\u4ee5\u6839\u636e\u7ed9\u5b9a\u7684\u5143\u7d20\u96c6\u5408\uff0c\u751f\u6210\u5bf9\u5e94\u7684 Set \u96c6\u5408\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u58f0\u660e int \u7c7b\u578b\u7684\u6570\u7ec4\uff0c\u91cc\u9762\u5305\u542b\u91cd\u590d\u7684\u5143\u7d20\n  var list = <int>[1, 2, 3, 2, 1];\n  \/\/ 2. \u8c03\u7528 Set.form() \u751f\u6210 Set \u96c6\u5408\n  var sets = Set<int>.from(list);\n  \/\/ 3. \u8f93\u51fa {1, 2, 3}\uff0c\u91cd\u590d\u7684\u5143\u7d20\u4f1a\u88ab\u8fc7\u6ee4\u6389\n  print(sets);\n}<\/code><\/pre>\n
1.2.3 Set<\u7c7b\u578b>.unmodifiable(\u53ef\u8fed\u4ee3\u7684\u96c6\u5408)<\/h4>\n
\u8c03\u7528 unmodifiable<\/code> \u6784\u9020\u51fd\u6570\uff0c\u53ef\u4ee5\u6839\u636e\u7ed9\u5b9a\u7684\u5143\u7d20\u96c6\u5408\uff0c\u521b\u5efa\u51fa\u4e00\u4e2a\u4e0d\u53ef\u4fee\u6539\u7684 Set \u96c6\u5408<\/strong>\uff0c\u4e0d\u5141\u8bb8\u4fee\u6539\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u4fe1\u606f\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u58f0\u660e int \u7c7b\u578b\u7684\u6570\u7ec4\uff0c\u91cc\u9762\u5305\u542b\u91cd\u590d\u7684\u5143\u7d20\n  var list = <int>[1, 2, 3, 2, 1];\n  \/\/ 2. \u8c03\u7528 Set.form() \u751f\u6210 Set \u96c6\u5408\n  var sets = Set<int>.unmodifiable(list);\n  \/\/ 3. \u8f93\u51fa {1, 2, 3}\uff0c\u91cd\u590d\u7684\u5143\u7d20\u4f1a\u88ab\u8fc7\u6ee4\u6389\n  print(sets);\n\n  \/\/ 4. \u5220\u9664\uff0c\u6dfb\u52a0\u7b49\u64cd\u4f5c\u4f1a\u62a5\u9519\n  \/\/ \u62a5\u9519\uff1aCannot change an unmodifiable set\n  \/\/ sets.remove(1);\n  \/\/ sets.add(4);\n}<\/code><\/pre>\n
2. \u64cd\u4f5c Set \u5143\u7d20<\/h2>\n
2.1 \u6dfb\u52a0\u5143\u7d20<\/h3>\n
\u53ef\u4ee5\u8c03\u7528 add<\/code> \u548c addAll<\/code> \u65b9\u6cd5\u5411 Set \u4e2d\u6dfb\u52a0\u5143\u7d20\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u5b9a\u4e49 Set \u96c6\u5408\n  var colors = <String>{'red'};\n\n  \/\/ 2. \u5355\u4e2a\u6dfb\u52a0\u5143\u7d20\n  colors.add('green');\n\n  \/\/ 3. \u4e00\u6b21\u6027\u6dfb\u52a0\u591a\u4e2a\u5143\u7d20\n  colors.addAll(['blue', 'purple', 'cyan']);\n\n  \/\/ \u8f93\u51fa {red, green, blue, purple, cyan}\n  print(colors);\n}<\/code><\/pre>\n
2.2 \u79fb\u9664\u5143\u7d20<\/h3>\n
\u8c03\u7528 remove<\/code> \u548c removeAll<\/code> \u65b9\u6cd5\u53ef\u4ee5\u4ece\u96c6\u5408\u4e2d\u79fb\u9664\u5143\u7d20\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u5b9a\u4e49 Set \u96c6\u5408\n  var colors = <String>{'red', 'blue', 'cyan', 'purple', 'orange'};\n\n  \/\/ 2. \u79fb\u9664\u5355\u4e2a\u5143\u7d20\n  colors.remove('blue');\n  \/\/ 3. \u8f93\u51fa {red, cyan, purple, orange}\n  print(colors);\n\n  \/\/ 4. \u4e00\u6b21\u6027\u79fb\u9664\u591a\u4e2a\u5143\u7d20\n  colors.removeAll(['cyan', 'purple']);\n  \/\/ 5. \u8f93\u51fa {red, orange}\n  print(colors);\n}<\/code><\/pre>\n
2.3 \u6e05\u7a7a\u5143\u7d20<\/h3>\n
\u8c03\u7528 clear<\/code> \u65b9\u6cd5\u53ef\u4ee5\u6e05\u7a7a Set \u96c6\u5408\u4e2d\u7684\u5143\u7d20\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
void main(List<String> args) {\n  \/\/ 1. \u5b9a\u4e49 Set \u96c6\u5408\n  var colors = <String>{'red', 'blue', 'cyan'};\n\n  \/\/ 2. \u8c03\u7528 clear \u65b9\u6cd5\u6e05\u7a7a Set\n  colors.clear();\n\n  \/\/ 3. \u8f93\u51fa true\uff0c\u8bc1\u660e\u96c6\u5408\u5df2\u88ab\u6e05\u7a7a\n  print(colors.isEmpty);\n}<\/code><\/pre>\n
3. Set \u5e38\u7528\u65b9\u6cd5<\/h2>\n
3.1 \u662f\u5426\u5305\u542b\u5bf9\u5e94\u7684\u5143\u7d20<\/h3>\n
    \n
  1. contains<\/code> \u7528\u6765\u5224\u65ad\u662f\u5426\u5305\u542b\u5355\u4e2a\u5143\u7d20<\/li>\n
  2. containsAll<\/code> \u7528\u6765\u5224\u65ad\u662f\u5426\u5305\u542b\u6240\u6709\u6307\u5b9a\u7684\u5143\u7d20<\/li>\n<\/ol>\n
    \u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  \/\/ 1. \u5b9a\u4e49 Set \u96c6\u5408\n  var colors = <String>{'red', 'blue', 'cyan'};\n\n  print(colors.contains('red')); \/\/ true\n  print(colors.contains('white')); \/\/ false\n  print(colors.containsAll(['red', 'blue'])); \/\/ true\n  print(colors.containsAll(['red', 'white'])); \/\/ false\n}<\/code><\/pre>\n
    3.2 difference<\/h3>\n
    \u96c6\u5408A.difference(\u96c6\u5408B)<\/code> \u5faa\u73af\u96c6\u5408A\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\uff0c\u5982\u679c\u5f53\u524d\u5faa\u73af\u7684\u5143\u7d20\u4e0d\u5305\u542b\u5728\u96c6\u5408B\u4e2d\uff0c\u5219\u628a\u5f53\u524d\u5143\u7d20\u6536\u96c6\u5230\u4e00\u4e2a\u65b0 Set \u4e2d\u8fd4\u56de\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n  var colorsB = <String>{'blue', 'white', 'black', 'cyan'};\n\n  var diff = colorsA.difference(colorsB);\n  \/\/ \u8f93\u51fa {red, orange}\n  print(diff);\n}<\/code><\/pre>\n
    3.3 intersection<\/h3>\n
    intersection<\/code> \u65b9\u6cd5\u7528\u6765\u63d0\u53d6\u4e24\u4e2a\u96c6\u5408\u76f8\u4ea4\uff08\u5171\u6709\uff09\u7684\u5143\u7d20\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n  var colorsB = <String>{'blue', 'white', 'black', 'cyan'};\n\n  var result = colorsA.intersection(colorsB);\n  \/\/ \u8f93\u51fa {blue, cyan}\n  print(result);\n}<\/code><\/pre>\n
    3.4 union<\/h3>\n
    union<\/code> \u65b9\u6cd5\u7528\u6765\u5408\u5e76\u4e24\u4e2a Set \u96c6\u5408\uff0c\u5e76\u8fd4\u56de\u5408\u5e76\u540e\u7684\u65b0 Set \u96c6\u5408\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n  var colorsB = <String>{'blue', 'white', 'black', 'cyan'};\n\n  var result = colorsA.union(colorsB);\n  \/\/ \u8f93\u51fa {red, blue, cyan, orange, white, black}\n  print(result);\n}<\/code><\/pre>\n
    3.5 lookup<\/h3>\n
    lookup<\/code> \u65b9\u6cd5\u7528\u6765\u4ece Set \u96c6\u5408\u4e2d\u67e5\u627e\u5bf9\u5e94\u7684\u5143\u7d20\uff0c\u5982\u679c\u627e\u4e0d\u5230\u5c31\u8fd4\u56de null\uff0c\u5982\u679c\u627e\u5230\u4e86\u5c31\u8fd4\u56de\u8fd9\u4e2a\u5143\u7d20\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n\n  var result1 = colorsA.lookup('red');\n  \/\/ \u80fd\u627e\u5230\uff0c\u8f93\u51fa red\n  print(result1);\n\n  var result2 = colorsA.lookup('black');\n  \/\/ \u627e\u4e0d\u5230\uff0c\u8f93\u51fa null\n  print(result2);\n}<\/code><\/pre>\n
    3.6 retainAll<\/h3>\n
    \u96c6\u5408A.retainAll(\u96c6\u5408B)<\/code> \u4ece Set \u96c6\u5408A\u4e2d\u4fdd\u7559\u96c6\u5408B\u4e2d\u7684\u6240\u6709\u5143\u7d20\uff0c\u4e0d\u5305\u542b\u5728\u96c6\u5408B\u4e2d\u7684\u5143\u7d20\u5c06\u4ece\u96c6\u5408A\u4e2d\u79fb\u9664\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n\n  \/\/ \u6ce8\u610f\uff1aretainAll \u65b9\u6cd5\u4f1a\u4fee\u6539\u539f\u96c6\u5408 colorsA\n  colorsA.retainAll(['red', 'blue']);\n  \/\/ \u8f93\u51fa {red, blue}\n  print(colorsA);\n}<\/code><\/pre>\n
    3.7 retainWhere<\/h3>\n
    retainWhere<\/code> \u65b9\u6cd5\u53ef\u4ee5\u628a\u7b26\u5408 where \u6761\u4ef6\u7684\u5143\u7d20\u4fdd\u7559\u4e0b\u6765\uff0c\u53bb\u9664\u4e0d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n\n  \/\/ \u628a\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\u4fdd\u7559\u4e0b\u6765\n  colorsA.retainWhere((element) => element.contains('e'));\n  \/\/ \u8f93\u51fa {red, blue, orange}\n  print(colorsA);\n}<\/code><\/pre>\n
    3.8 join<\/h3>\n
    join<\/code> \u65b9\u6cd5\u7528\u6765\u6839\u636e\u6307\u5b9a\u7684\u5b57\u7b26\u4e32\u62fc\u63a5\u96c6\u5408\u4e2d\u7684\u6240\u6709\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u62fc\u63a5\u7684\u7ed3\u679c\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  var colorsA = <String>{'red', 'blue', 'cyan', 'orange'};\n\n  \/\/ \u6839\u636e\u6307\u5b9a\u7684\u5b57\u7b26\u4e32\u62fc\u63a5 Set \u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\n  var result = colorsA.join(', ');\n  \/\/ \u8f93\u51fa\u5b57\u7b26\u4e32 red, blue, cyan, orange\n  print(result);\n}<\/code><\/pre>\n
    3.9 Set \u4e2d\u7684 if \u548c for<\/h3>\n
    Set \u96c6\u5408\u4e2d\u652f\u6301\u4f7f\u7528 if<\/code> \u548c for<\/code>\uff0c\u7528\u6cd5\u548c List \u6570\u7ec4\u76f8\u540c\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
    void main(List<String> args) {\n  \/\/ \u5b9a\u4e49\u5e03\u5c14\u53d8\u91cf\n  var flag = true;\n\n  var sets = <dynamic>{\n    'red',\n    \/\/ Set \u4e2d\u7684 if\n    if (flag) 'cyan',\n    \/\/ Set \u4e2d\u7684 for\n    for (var i = 0; i < 3; i++) '#${i}'\n  };\n\n  \/\/ \u8f93\u51fa {red, cyan, #0, #1, #2}\n  print(sets);\n}<\/code><\/pre>\n
    \u5173\u4e8e Set \u96c6\u5408\u7684\u66f4\u591a\u7528\u6cd5\uff0c\u8bf7\u53c2\u8003 Set \u7684\u5b98\u65b9\u6587\u6863<\/a>\u3002<\/p>\n
    \n
    \u7248\u6743\u5f52\u4f5c\u8005 \u00a9\u5218\u9f99\u5bbe<\/strong> \u6240\u6709\uff0c\u672c\u6587\u7ae0\u672a\u7ecf\u4f5c\u8005\u5141\u8bb8\uff0c\u7981\u6b62\u79c1\u81ea\u8f6c\u8f7d\uff01<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"
    \u7248\u6743\u5f52\u4f5c\u8005 \u00a9\u5218\u9f99\u5bbe \u6240\u6709\uff0c\u672c\u6587\u7ae0\u672a\u7ecf\u4f5c\u8005\u5141\u8bb8\uff0c\u7981\u6b62\u79c1\u81ea\u8f6c\u8f7d\uff01 \u5728 Dart \u4e2d\uff0cSet \u662f\u4e00\u4e2a\u65e0\u5e8f\u7684\u3001\u5143\u7d20\u552f\u4e00\u7684\u96c6\u5408\u3002 \u7531\u4e8e Set \u662f\u65e0\u5e8f\u7684\uff0c\u6240\u4ee5\u65e0\u6cd5\u50cf List \u6570\u7ec4\u90a3\u6837\u901a\u8fc7\u7d22\u5f15\uff08\u4e0b\u6807\uff09\u83b7\u53d6 Set \u4e2d\u7684\u5143\u7d20\u3002 1. \u521b\u5efa Set \u96c6\u5408 1.1 \u57fa\u4e8e\u5b57\u9762\u91cf\u521b\u5efa Set \u6e29\u99a8\u63d0\u793a\uff1a\u5c3d\u7ba1 Set \u7c7b\u578b(type) \u4e00\u76f4\u90fd\u662f Dart \u7684\u4e00\u9879\u6838\u5fc3\u529f\u80fd\uff0c\u4f46\u662f Set \u5b57\u9762\u91cf(literals) \u662f\u5728 Dart 2.2 \u4e2d\u624d\u52a0\u5165\u7684\u3002 1.1.1 \u5f3a\u7c7b\u578b\u7684 Set \u58f0\u660e Set \u5b57\u9762\u91cf\u7684\u8bed\u6cd5\u662f <\u7c7b\u578b>{}\u3002\u8fd9\u91cc\u9700\u8981\u7279\u522b\u63d0\u9192\u4e0b\uff0c\u5de6\u4fa7\u7684 <\u7c7b\u578b> \u662f\u5fc5\u987b\u7684\uff0c\u5982\u679c\u7701\u7565\u4e86\u7c7b\u578b\uff0c\u53ea\u5199\u4e86 {}\uff0c\u90a3\u4e48\u4f1a\u88ab Dart \u7f16\u8bd1\u6210 Map \u7684\u5b57\u9762\u91cf\u3002\u4e0b\u9762\u7684\u4ee3\u7801\u6f14\u793a\u4e86\u5982\u4f55\u58f0\u660e Set \u5b57\u9762\u91cf\uff1a void main(List<String> args) { \/\/ 1. \u58f0\u660e\u5b57\u7b26\u4e32\u7c7b\u578b\u7684 Set \u96c6\u5408 var names = <String>{'liulongbin', 'escook'}; \/\/ 2. \u5411 Set \u4e2d\u6dfb\u52a0\u91cd\u590d\u7684\u5143\u7d20 names.add('liulongbin'); \/\/ 3. \u7531\u4e8e Set \u4e2d\u7684\u5143\u7d20\u5177\u6709\u552f\u4e00\u6027\uff0c\u6240\u4ee5\u91cd\u590d\u6dfb\u52a0\u7684\u5143\u7d20\u4f1a\u88ab\u5c4f\u853d \/\/ \u8f93\u51fa {liulongbin, escook} print(names); } 1.1.2 dynamic \u7684 Set \u5f3a\u7c7b\u578b\u7684 Set \u53ea\u80fd\u6dfb\u52a0\u7c7b\u578b\u76f8\u540c\u7684\u5143\u7d20\uff0c\u5982\u679c\u60f3\u521b\u5efa dynamic \u7c7b\u578b\u7684 Set\uff0c\u63a8\u8350\u4f7f\u7528 <dynamic>{} \u7684\u65b9\u5f0f\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a void main(List<String> args) { \/\/ 1. \u521b\u5efa\u52a8\u6001\u7c7b\u578b\u7684 Set\uff0c\u53ef\u4ee5\u5411\u96c6\u5408\u4e2d\u63d2\u5165\u4efb\u4f55\u7c7b\u578b\u7684\u5143\u7d20 var names = <dynamic>{'liulongbin', 666}; \/\/ 2. \u8f93\u51fa {liulongbin, 666} print(names); } 1.2 \u57fa\u4e8e\u6784\u9020\u51fd\u6570\u521b\u5efa Set 1.2.1 Set<\u7c7b\u578b>.identity() Set \u96c6\u5408\u7684 identity \u6784\u9020\u51fd\u6570\uff0c\u7528\u6765\u521b\u5efa\u7a7a\u767d\u7684 Set \u96c6\u5408\u3002\u5982\u679c\u6307\u5b9a\u4e86\u7c7b\u578b\uff0c\u5219\u662f\u5f3a\u7c7b\u578b\u7684 Set\uff1b\u5982\u679c\u7701\u7565\u4e86 <\u7c7b\u578b> \u6216\u63d0\u4f9b\u7684\u7c7b\u578b\u662f <dynamic>\uff0c\u5219\u521b\u5efa\u7684\u662f\u52a8\u6001\u7c7b\u578b\u7684 Set\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a void main(List<String> args) { \/\/ 1.1 \u521b\u5efa String \u5f3a\u7c7b\u578b\u7684\u7a7a Set var names = Set<String>.identity(); \/\/ 1.2 \u6dfb\u52a0\u5143\u7d20 names.add('liulongbin'); names.add('escook'); \/\/ 1.3 \u8f93\u51fa {liulongbin, escook} print(names); \/\/ —- \/\/ 2.1 \u521b\u5efa\u52a8\u6001\u7c7b\u578b\u7684 Set var sets = Set<dynamic>.identity(); \/\/ 2.2 \u6dfb\u52a0\u5b57\u7b26\u4e32\u3001\u6570\u5b57\u3001\u5e03\u5c14\u5143\u7d20 sets.add('liulongbin'); sets.add(666); sets.add(true); \/\/ 2.3 \u8f93\u51fa {liulongbin, 666, true} print(sets); } 1.2.2 Set<\u7c7b\u578b>.from(\u53ef\u8fed\u4ee3\u7684\u96c6\u5408) \u8c03\u7528 from \u6784\u9020\u51fd\u6570\uff0c\u53ef\u4ee5\u6839\u636e\u7ed9\u5b9a\u7684\u5143\u7d20\u96c6\u5408\uff0c\u751f\u6210\u5bf9\u5e94\u7684 Set \u96c6\u5408\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a void main(List<String> args) { \/\/ 1. \u58f0\u660e int \u7c7b\u578b\u7684\u6570\u7ec4\uff0c\u91cc\u9762\u5305\u542b\u91cd\u590d\u7684\u5143\u7d20 var list = <int>[1, 2, 3, 2, 1]; \/\/ 2. \u8c03\u7528 Set.form() \u751f\u6210 Set \u96c6\u5408 var sets = Set<int>.from(list); \/\/ 3. \u8f93\u51fa {1, 2, 3}\uff0c\u91cd\u590d\u7684\u5143\u7d20\u4f1a\u88ab\u8fc7\u6ee4\u6389 print(sets); } 1.2.3 Set<\u7c7b\u578b>.unmodifiable(\u53ef\u8fed\u4ee3\u7684\u96c6\u5408) \u8c03\u7528 unmodifiable \u6784\u9020\u51fd\u6570\uff0c\u53ef\u4ee5\u6839\u636e\u7ed9\u5b9a\u7684\u5143\u7d20\u96c6\u5408\uff0c\u521b\u5efa\u51fa\u4e00\u4e2a\u4e0d\u53ef\u4fee\u6539\u7684 Set \u96c6\u5408\uff0c\u4e0d\u5141\u8bb8\u4fee\u6539\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u4fe1\u606f\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a void main(List<String> args) { \/\/ 1. \u58f0\u660e int \u7c7b\u578b\u7684\u6570\u7ec4\uff0c\u91cc\u9762\u5305\u542b\u91cd\u590d\u7684\u5143\u7d20 var list = <int>[1, 2, 3, 2, …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[9],"class_list":["post-203","post","type-post","status-publish","format-standard","hentry","category-dart","tag-dart"],"_links":{"self":[{"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/posts\/203","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/comments?post=203"}],"version-history":[{"count":2,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/posts\/203\/revisions"}],"predecessor-version":[{"id":576,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/posts\/203\/revisions\/576"}],"wp:attachment":[{"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/media?parent=203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/categories?post=203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.escook.cn\/index.php\/wp-json\/wp\/v2\/tags?post=203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}