{"id":1805,"date":"2023-09-22T07:13:46","date_gmt":"2023-09-21T22:13:46","guid":{"rendered":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/?p=1805"},"modified":"2023-09-22T10:38:48","modified_gmt":"2023-09-22T01:38:48","slug":"dart-programmer-51","status":"publish","type":"post","link":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/2023\/09\/22\/dart-programmer-51\/","title":{"rendered":"Records (@Dart3.0)"},"content":{"rendered":"\n

Records\uc5d0 \ub300\ud55c \ub2e4\uc74c \uc124\uba85\uc740, Dart \uacf5\uc2dd \uc0ac\uc774\ud2b8\uc758 \ub0b4\uc6a9(\uc544\ub798\uc758 \ucd9c\ucc98 \ucc38\uc870)<\/a>\uc744 \uae30\ubc18\uc73c\ub85c, \ub3c5\uc790\uc758 \uc774\ud574\ub97c \ub3d5\uae30 \uc704\ud55c \ucd94\uac00\uc801\uc778 \uae00\uc744 \ud3ec\ud568\ud558\uac70\ub098, \ucd9c\ucc98\uc758 \uae00\uc744 \uc218\uc815\ud558\ub294 \ubc29\uc2dd\uc73c\ub85c \uc791\uc131\ud558\uc600\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n

Dart 3.0 \ubd80\ud130 \uc9c0\uc6d0\ud558\ub294 Records\ub294 anonymous, immutable \ud55c \ud2b9\uc131\uc744 \uac16\ub294 \uc0c8\ub85c\uc6b4 \ud615\ud0dc\uc758 aggregate type \uc785\ub2c8\ub2e4. \ub530\ub77c\uc11c \ud558\ub098\uc758 \uac1d\uccb4\uc5d0 \ubcf5\uc218\uc758 \uac1d\uccb4\ub97c \uc800\uc7a5\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ud558\uc9c0\ub9cc \ub2e4\ub978 \ubcf5\uc218\uc758 \uac12\uc744 \uac16\ub294 collection types(\uc608\ub97c \ub4e4\uc5b4 List, Map \ub4f1)\ub4e4\uacfc \ub2e4\ub974\uac8c \uace0\uc815\ub41c \ud06c\uae30\uc640 \ud0c0\uc785\uc744 \uac16\uc2b5\ub2c8\ub2e4. <\/p>\n\n\n\n

Records \ud0c0\uc785\uc758 \uac12\uc740 \ubcc0\uc218\uc5d0 \uc800\uc7a5\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ud568\uc218\uc758 \uc785\ub825 \uac12\uc73c\ub85c \uc804\ub2ec\ud558\uac70\ub098, \ub9ac\ud134 \uac12\uc73c\ub85c \uc804\ub2ec \ubc1b\uc744 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uadf8\ub9ac\uace0 List, Map, Set\uacfc \uac19\uc740 collection type\uc5d0 \uc800\uc7a5\ud560 \uc218\ub3c4 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n

Records\ub294 \uc27c\ud45c\ub85c \uad6c\ubd84\ud55c \uac12\ub4e4\uc774 \uc18c\uad04\ud638 \uc548\uc5d0 \ub098\uc5f4\ub41c \ud615\ud0dc\ub85c \ud45c\ud604\ud569\ub2c8\ub2e4. \uc774 \uacbd\uc6b0 named \ubc29\uc2dd\uacfc positional \ubc29\uc2dd\uc744 \ud63c\uc6a9\ud574\uc11c \uc0ac\uc6a9\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc989 \uc544\ub798\uc758 \uc608\uc81c\uc5d0\uc11c ‘first’\uc640 ‘last’\ub294 positional \ubc29\uc2dd\uc73c\ub85c, \ucd94\ud6c4 \uc21c\uc11c\uc5d0 \uc758\ud574\uc11c \uac12\uc5d0 \uc811\uadfc\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. 2\uc640 true \uac12\uc740 \uac01\uac01 a\uc640 b\uc758 \uc774\ub984\uc744 \ubd80\uc5ec\ud55c \ubc29\uc2dd\uc785\ub2c8\ub2e4. <\/p>\n\n\n\n

var record = ('first', a: 2, b: true, 'last');<\/code><\/pre>\n\n\n\n
Records\uc5d0 \ud3ec\ud568\ub41c \ud56d\ubaa9(field)\uc740 \uc790\ub3d9\uc73c\ub85c \uc0dd\uc131\ub41c getter\uc5d0 \uc758\ud574\uc11c \uc811\uadfc \uac00\ub2a5\ud569\ub2c8\ub2e4. \uadf8\ub9ac\uace0 Records\ub294 immutable\ud558\uae30\uc5d0 setter\ub294 \uc5c6\uc2b5\ub2c8\ub2e4. Records\uc5d0 \ud3ec\ud568\ub41c \ud56d\ubaa9\uc774 named \ubc29\uc2dd\uc778 \uacbd\uc6b0\ub294 Record\uc758 \uc774\ub984\uc5d0 \uc810(.) \uc5f0\uc0b0\uc790\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc811\uadfc\ud569\ub2c8\ub2e4. Positional \ud56d\ubaa9\uc740 $<position> \ubb38\ubc95\uc744 \uc0ac\uc6a9\ud569\ub2c8\ub2e4. \ub2e4\uc74c\uc740 Record\uc778 record\uc758 \ud56d\ubaa9\uc744 \uc811\uadfc\ud558\ub294 \uc608\uc81c\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n
var record = ('first', a: 2, b: true, 'last');\n\nprint(record.$1); \/\/ Prints 'first'\nprint(record.a); \/\/ Prints 2\nprint(record.b); \/\/ Prints true\nprint(record.$2); \/\/ Prints 'last'<\/code><\/pre>\n\n\n\n
\uc608\uc81c\uc5d0\uc11c \uc774\ub984\uc774 a\uc640 b\uc778 \ud56d\ubaa9\uc744 record.a\uc640 record.b\ub85c \uc0ac\uc6a9\ud558\ub294 \uac83\uc740 \uba85\ud655\ud569\ub2c8\ub2e4. \uadf8\ub7f0\ub370 \uc774\ub984\uc774 \uc5c6\uae30\uc5d0 \uc704\uce58\ub85c \uc811\uadfc\ud574\uc57c \ud558\ub294 ‘first’\uc640 ‘last’\uc5d0 \ub300\ud574\uc11c\ub294 \uc124\uba85\uc774 \ud544\uc694\ud569\ub2c8\ub2e4. \uac04\ub2e8\ud558\uac8c \uc774\uc57c\uae30 \ud558\uba74, Records\uac00 \ud3ec\ud568\ud558\uace0 \uc788\ub294 \ud56d\ubaa9 \uc911 named \ud56d\ubaa9\uc774 \uc544\ub2cc \uccab\ubc88\uc9f8 Positional \ud56d\ubaa9\uc5d0 \ub300\ud574\uc11c $1\uc758 \uc784\uc2dc \uc774\ub984\uc744 \ubd80\uc5ec\ud558\uba70, \uadf8 \ub2e4\uc74c\uc758 Positional \ud56d\ubaa9\uc5d0 \ub300\ud574\uc11c 1\uc758 \uac12\uc774 \uc99d\uac00\ud55c $2\ub97c \ubd80\uc5ec\ud569\ub2c8\ub2e4. \uadf8\ub9ac\uace0 (‘first’, a: 2, b: true, ‘last’)\uc740 immutable \ud558\uace0 setter\uac00 \uc5c6\uae30\uc5d0, record.$1 = ‘third’ \ud639\uc740 record.a = 3\uc758 \uad6c\ubb38\uc740 \ub3d9\uc791\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n
Records \ud0c0\uc785\uc740 \ud568\uc218\uc758 \uc785\ub825 \ud30c\ub77c\uba54\ud130\ub85c \uc804\ub2ec\ud560 \uc218 \uc788\uace0, \ub9ac\ud134 \uac12\uc73c\ub85c\ub3c4 \uc804\ub2ec \ubc1b\uc744 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ub2e4\uc74c\uc758 \uc608\uc81c\ub294 (int, int) \ud0c0\uc785\uc758 Record\ub97c swap() \ud568\uc218\uc758 \uc785\ub825 \ud30c\ub77c\uba54\ud130\ub85c \uc804\ub2ec\ud55c \ud6c4, \ub2e4\uc2dc (int, int) \ud0c0\uc785\uc758 \uacb0\uacfc\ub85c \ub9ac\ud134 \ubc1b\ub294 \uacbd\uc6b0\ub97c \ubcf4\uc5ec\uc90d\ub2c8\ub2e4.<\/p>\n\n\n\n
(int, int) swap((int, int) record) {\n  var (a, b) = record;\n  return (b, a);\n}<\/code><\/pre>\n\n\n\n
Records \ud0c0\uc785\uc73c\ub85c \ubcc0\uc218\ub97c \uc0dd\uc131\ud558\ub294 \uac83\ub3c4 \uac00\ub2a5\ud569\ub2c8\ub2e4. \ub2e4\uc74c\uc740 Positional\ud55c \ud56d\ubaa9\uc778 String\uacfc int\ub97c \uac16\ub294 Record \ud0c0\uc785\uc758 \ubcc0\uc218 record\ub97c \uc0dd\uc131\ud558\uace0, \uac12\uc744 \uc800\uc7a5\ud558\ub294 \uc608\uc81c\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n
\/\/ Record type annotation in a variable declaration:\n(String, int) record;\n\n\/\/ Initialize it with a record expression:\nrecord = ('A string', 123);<\/code><\/pre>\n\n\n\n
Dart \uc5b8\uc5b4\uc758 \uc785\ub825 \ud30c\ub77c\uba54\ud130\ub97c \uc804\ub2ec\ubc1b\ub294 \ubc29\ubc95\uc5d0\uc11c \ub2e4\ub8ec named \ud30c\ub77c\uba54\ud130\ub97c \ud65c\uc6a9\ud558\uc5ec, Records \ud0c0\uc785\uc758 \ubcc0\uc218 \uc0dd\uc131\uc2dc named \ud30c\ub77c\uba54\ud130\ub97c \uac16\ub3c4\ub85d \ud558\ub294 \uac83\ub3c4 \uac00\ub2a5\ud569\ub2c8\ub2e4. \uc774 \uacbd\uc6b0 \ud568\uc218\uc758 \uc785\ub825 \ud30c\ub77c\uba54\ud130\ub97c named \ubc29\uc2dd\uc73c\ub85c \ub9cc\ub4e4\uae30 \uc704\ud558\uc5ec \uc0ac\uc6a9\ud55c \uc911\uad04\ud638({}) \ubb38\ubc95\uc744 \ub3d9\uc77c\ud558\uac8c \uc0ac\uc6a9\ud569\ub2c8\ub2e4. \ub2e4\uc74c\uc740 Records \ud0c0\uc785\uc758 \ubcc0\uc218 record\ub97c \uc0dd\uc131\ud558\uba74\uc11c, \ud3ec\ud568\ub418\ub294 \uccab\ubc88\uc9f8 \ud56d\ubaa9\uc758 \uc774\ub984\uc740 a\ub85c \ud558\uace0 \ub450\ubc88\uc9f8 \ud56d\ubaa9\uc758 \uc774\ub984\uc740 b\ub85c \ud558\ub294 \uac83\uc744 \ubcf4\uc5ec\uc90d\ub2c8\ub2e4.<\/p>\n\n\n\n
\/\/ Record type annotation in a variable declaration:\n({int a, bool b}) record;\n\n\/\/ Initialize it with a record expression:\nrecord = (a: 123, b: true);<\/code><\/pre>\n\n\n\n
Named \ubc29\uc2dd\uc744 \uc0ac\uc6a9\ud558\uae30\uc5d0, \ub2f9\uc5f0\ud788 record = (b: true, a: 123) \ud45c\ud604\ub3c4 \ub3d9\uc77c\ud55c \uacb0\uacfc\ub97c \ub9cc\ub4ed\ub2c8\ub2e4.<\/p>\n\n\n\n
\uc8fc\uc758\ud574\uc57c\ud560 \uc0ac\ud56d\uc740, \ud56d\ubaa9\uc758 \uc774\ub984\uc778 a\uc640 b\ub3c4 record\uc758 \ud0c0\uc785 \uc548\uc5d0 \uace0\uc815\uc801\uc778 \ud615\ud0dc\ub85c \uc124\uc815\ub41c\ub2e4\ub294 \uc810 \uc785\ub2c8\ub2e4. \uc774\ub294 \ub2e4\uc74c\uc758 \uc608\uc81c\uc5d0\uc11c \uc54c \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n
({int a, int b}) recordAB = (a: 1, b: 2);\n({int x, int y}) recordXY = (x: 3, y: 4);\n\n\/\/ Compile error! These records don't have the same type.\n\/\/ recordAB = recordXY;<\/code><\/pre>\n\n\n\n
recordAB\uc640 recordXY\ub294 Records \ud0c0\uc785\uc774\uba70, \ub3d9\uc77c\ud558\uac8c \uc815\uc218 \ub450 \uac1c\ub97c \ud56d\ubaa9\uc73c\ub85c \uac16\uc2b5\ub2c8\ub2e4. \ud558\uc9c0\ub9cc, named \ud30c\ub77c\uba54\ud130 \ubc29\uc2dd\uc744 \uc0ac\uc6a9\ud558\uae30\uc5d0, \ub450 \ud56d\ubaa9\uc758 \ud0c0\uc785 \ubfd0 \uc544\ub2c8\ub77c \ud56d\ubaa9\uc5d0 \uc8fc\uc5b4\uc9c4 \uc774\ub984\ub3c4 \ub3d9\uc77c\ud574\uc57c \ube44\uad50\uac00 \uac00\ub2a5\ud558\uba70, \uc774\ub984\uc774 \ub2e4\ub978 \ud56d\ubaa9\uc744 \uac00\uc9c4 Records \uac04\uc758 \ube44\uad50\ub294 \ubd88\uac00\ub2a5\ud569\ub2c8\ub2e4. Named \ubc29\uc2dd\uc774 \uc544\ub2cc \uacbd\uc6b0\ub294 \ub2f9\uc5f0\ud788 \ud56d\ubaa9\uc758 \ud0c0\uc785\ub9cc \ub3d9\uc77c\ud558\uba74 \ube44\uad50\uac00 \uac00\ub2a5\ud558\uba70, \uc774\uc5d0 \ub300\ud55c \uc608\uc81c\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n
(int a, int b) recordAB = (1, 2);\n(int x, int y) recordXY = (3, 4);\n\nrecordAB = recordXY; \/\/ OK.<\/code><\/pre>\n\n\n\n
Dart \uc5b8\uc5b4\uc5d0\uc11c Records\ub294 shape\uc5d0 \uc758\ud574\uc11c \ucc98\ub9ac\ub41c\ub2e4\uace0 \uc815\uc758\ud569\ub2c8\ub2e4. Shape\ub294 \ud544\ub4dc\uc758 \uc9d1\ud55c, \ud544\ub4dc\uc758 \ud0c0\uc785, \uadf8\ub9ac\uace0 \ud544\ub4dc\uc758 \uc774\ub984 \ub4f1\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4. \ub2e4\uc74c\uc758 \uc608\uc81c\uc5d0\uc11c\ub294 pair\uc5d0 \uc8fc\uc5b4\uc9c0\ub294 (42, ‘a’)\uc5d0 \ub300\ud574\uc11c, \uac01\uac01 num \ud0c0\uc785\uacfc Object \ud0c0\uc785\uc73c\ub85c \ub9e4\ud551\ub418\uc5b4 \ucc98\ub9ac\ub418\ub294 \uac83\uc744 \ubcf4\uc5ec\uc90d\ub2c8\ub2e4.<\/p>\n\n\n\n
(num, Object) pair = (42, 'a');\n\nvar first = pair.$1; \/\/ Static type `num`, runtime type `int`.\nvar second = pair.$2; \/\/ Static type `Object`, runtime type `String`.<\/code><\/pre>\n\n\n\n
Records\uc758 \uac00\uc7a5 \uc190\uc26c\uc6b4 \uc0ac\uc6a9 \ubc29\ubc95\uc740 \ubcf5\uc218\uc758 \uac12\uc744 \ub9ac\ud134\ud558\ub294 \ud568\uc218\uc785\ub2c8\ub2e4. \ub2e4\uc74c\uc758 \uc608\uc81c\ub294 userInfo() \ud568\uc218\uac00 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ub808\ucf54\ub4dc\uc758 \uc774\ub984 \ud544\ub4dc\uc640 \ub098\uc774 \ud544\ub4dc\uc758 \uac12\uc744 \ud568\uc218\uc758 \uacb0\uacfc\ub85c \ub9ac\ud134\ud558\ub294 \uc608\uc81c\ub97c \ubcf4\uc5ec\uc90d\ub2c8\ub2e4. <\/p>\n\n\n\n
\/\/ Returns multiple values in a record:\n(String, int) userInfo(Map<String, dynamic> json) {\n  return (json['name'] as String, json['age'] as int);\n}\n\nfinal json = <String, dynamic>{\n  'name': 'Dash',\n  'age': 10,\n  'color': 'blue',\n};\n\n\/\/ Destructures using a record pattern:\nvar (name, age) = userInfo(json);\n\n\/* Equivalent to:\n  var info = userInfo(json);\n  var name = info.$1;\n  var age  = info.$2;\n*\/<\/code><\/pre>\n\n\n\n
\ub9ac\ud134 \ub41c \uacb0\uacfc\ub294 \ubc1b\ub294 \ubd80\ubd84\uc5d0\uc11c \ubcfc \uc218 \uc788\ub4ef\uc774, \ub450 \uac1c\uc758 \uacb0\uacfc\uac00 name\uacfc age\uc5d0 \uac01\uac01 \ub9e4\ud551\ub418\ub294 \uac83\uc744 \ubcfc \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ubb3c\ub860 \ub450 \uac1c \uc774\uc0c1\uc758 \uac12\uc744 \ub9ac\ud134\ud558\ub294 \ubb38\uc7a5\uc744 List, Map, Set \ub4f1\uc758 collection type\uc744 \ud1b5\ud574\uc11c \uad6c\ud604\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ud558\uc9c0\ub9cc, \uc774\ub4e4\uc740 \ub450 \uac1c \ubcf4\ub2e4 \ub354 \ub9ce\uc740 \ub300\ub7c9\uc758 \ub370\uc774\ud130\ub97c \ub2e4\ub8e8\ub294 \ud0c0\uc785\uc73c\ub85c\uc11c, \uc8fc\uc5b4\uc9c4 \ub450 \uac1c\uc758 \uacb0\uacfc\ub97c \ub9ac\ud134\ud558\ub294 \ubc29\uc2dd\uc5d0 \ucd5c\uc120\uc758 \uae30\uc220\uc740 \uc544\ub2d9\ub2c8\ub2e4. \ub530\ub77c\uc11c, Dart 3.0\uc740 \ubc1c\uc804\ub41c \ubc29\ubc95\uc758 Records\ub97c \uc81c\uacf5\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n
<\/p>\n\n\n\n
[\ucd9c\ucc98] https:\/\/dart.dev\/language\/records<\/a><\/p>\n\n\n\n
[\ucc38\uc870] https:\/\/api.flutter.dev\/flutter\/dart-core\/Record-class.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
Records\uc5d0 \ub300\ud55c \ub2e4\uc74c \uc124\uba85\uc740, Dart \uacf5\uc2dd \uc0ac\uc774\ud2b8\uc758 \ub0b4\uc6a9(\uc544\ub798\uc758 \ucd9c\ucc98 \ucc38\uc870)\uc744 \uae30\ubc18\uc73c\ub85c, \ub3c5\uc790\uc758 \uc774\ud574\ub97c \ub3d5\uae30 \uc704\ud55c \ucd94\uac00\uc801\uc778 \uae00\uc744 \ud3ec\ud568\ud558\uac70\ub098, \ucd9c\ucc98\uc758 \uae00\uc744 \uc218\uc815\ud558\ub294 \ubc29\uc2dd\uc73c\ub85c \uc791\uc131\ud558\uc600\uc2b5\ub2c8\ub2e4. Dart 3.0 \ubd80\ud130 \uc9c0\uc6d0\ud558\ub294 Records\ub294 anonymous, immutable …<\/p>\n","protected":false},"author":1,"featured_media":1748,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[3],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/posts\/1805"}],"collection":[{"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/comments?post=1805"}],"version-history":[{"count":5,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/posts\/1805\/revisions"}],"predecessor-version":[{"id":1825,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/posts\/1805\/revisions\/1825"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/media\/1748"}],"wp:attachment":[{"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/media?parent=1805"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/categories?post=1805"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/mobilelab.khu.ac.kr\/wordpress\/wp-json\/wp\/v2\/tags?post=1805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}