{"id":4508,"date":"2025-01-12T22:21:35","date_gmt":"2025-01-12T13:21:35","guid":{"rendered":"https:\/\/www.wsmeguro.jp\/wp\/?p=4508"},"modified":"2025-01-13T11:45:10","modified_gmt":"2025-01-13T02:45:10","slug":"dart%e3%81%ae%e5%8b%89%e5%bc%b71%e2%88%921%ef%bc%9a%e5%a4%89%e6%95%b0%e3%81%a8%e3%83%87%e3%83%bc%e3%82%bf%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/www.wsmeguro.jp\/wp\/?p=4508","title":{"rendered":"Dart\u306e\u52c9\u5f371\u22122\uff1a\u5909\u6570\u3068\u30c7\u30fc\u30bf\u578b"},"content":{"rendered":"<p>ChatGPT\u5148\u751f\u306b\u76e3\u4fee\u3057\u3066\u9802\u3044\u3066Dart\u306e\u5b66\u7fd2\u3092\u518d\u958b\u3057\u307e\u3059\u3002<br \/>\n\u3053\u308c\u307e\u3067\u306e\u8a18\u8ff0\u306b\u4e0d\u8db3\u3057\u3066\u3044\u305f\u3068\u3053\u308d\u3092\u9069\u5b9c\u304f\u308f\u3048\u3066\u3044\u304d\u307e\u3059\u3002\u4eca\u56de\u306f\u3001\u5909\u6570\u3068\u30c7\u30fc\u30bf\u578b\u3067\u3059\u3002<\/p>\n<hr>\n<p>\u5909\u6570\u3068\u306f\u3001\u6570\u5024\u3084\u6587\u5b57\u5217\u7b49\u306e\u30c7\u30fc\u30bf\u3092\u4fdd\u5b58\u3057\u3066\u304a\u304f\u5165\u308c\u7269\u3067\u3001\u4f55\u3089\u304b\u306e\u540d\u524d\u3092\u3064\u3051\u307e\u3059\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nint year = 2025;<\/code><\/pre>\n<\/div>\n<p>\u3053\u308c\u3067\u3001\u5909\u6570year\u306b2025\u3068\u3044\u3046\u6574\u6570\u306e\u5024\u304c\u4fdd\u5b58\u3055\u308c\u305f\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\uff1cp\uff1e<\/p>\n<hr>\n<p>\u30c7\u30fc\u30bf\u578b\u3068\u306f\u3001\u5909\u6570\u306b\u5165\u3063\u3066\u3044\u308b\u5024\u306e\u7a2e\u985e\u3067\u3059\u3002\u5148\u307b\u3069\u306e\u4f8b\u306f\u6574\u6570\u3068\u3044\u3046\u3053\u3068\u3067int\u3092\u5192\u982d\u306b\u3064\u3051\u3066\u3001year\u306f\u6574\u6570\u3060\u3068\u660e\u793a\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<ol>\n<li>\u578b\u63a8\u8ad6<br \/>\nDart\u306f\u5909\u6570\u3092var\u3092\u3064\u3051\u3066\u6700\u521d\u306e\u5024\u3092\u4e0e\u3048\u308b\u3068\u52dd\u624b\u306b\u578b\u3092\u63a8\u5bdf\u3057\u3066\u304f\u308c\u307e\u3059\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nvar name = 'John';<\/code><\/pre>\n<\/div>\n<p>\u3053\u308c\u3067\u5909\u6570name\u306b\u306f\u6587\u5b57\u578b\u306b\u306a\u308a\u3001John\u304c\u5024\u3068\u3057\u3066\u4ee3\u5165\u3055\u308c\u307e\u3059\u3002\n<\/li>\n<li>null\u5b89\u5168\u6027<br \/>\nnull\u3068\u3044\u3046\u306e\u306f\u3001\u4f55\u3082\u306a\u3044\u72b6\u614b\u3067\u6574\u6570\u3067\u3082\u6587\u5b57\u3067\u3082\u306a\u3093\u3067\u3082\u306a\u3044\u72b6\u614b\u3067\u3059\u3002\u3053\u306e\u72b6\u614b\u3060\u3068\u51e6\u7406\u304c\u3067\u304d\u305a\u306b\u6b62\u307e\u3063\u3066\u3057\u307e\u3046\u3053\u3068\u304c\u591a\u3044\u306e\u3067\u3001\u666e\u901a\u306b\u5909\u6570\u3092\u5ba3\u8a00\u3057\u305f\u5834\u5408\u306f\u3001\u5fc5\u305a\u4f55\u304b\u3057\u3089\u306e\u5024\u304c\u5165\u3063\u3066\u3044\u308b\u72b6\u614b\u306b\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u305f\u3060\u3057\u3001object\u306e\u30e1\u30bd\u30c3\u30c9\u7b49\u3067null\u3092\u8a31\u5bb9\u3057\u3066\u3044\u308b\u5834\u5408\u3082\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30c7\u30fc\u30bf\u578b\u5f8c\u306b\uff1f\u3092\u3064\u3051\u3066\u5909\u6570\u3092\u5ba3\u8a00\u3057\u307e\u3059\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nString? name \/\/null\u3092\u8a31\u5bb9\u3059\u308b\u3002\r\n<\/code><\/pre>\n<\/div>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nvoid main() {\r\nString name;\r\nassert(name == null);\u3000\/\/null\u3092\u8a31\u5bb9\u3057\u306a\u3044\u306e\u3067\u3001\u3053\u3053\u3067\u30a8\u30e9\u30fc\u306b\u306a\u308b\r\n}\r\n<\/code><\/pre>\n<\/div>\n<\/li>\n<li>late<br \/>\nnull\u3092\u8a31\u5bb9\u3057\u306a\u3044\u3051\u3069\u3001\u3068\u308a\u3042\u3048\u305a\u3001\u5909\u6570\u3060\u3051\u5ba3\u8a00\u3059\u308b\u65b9\u6cd5\u3068\u3057\u3066late\u304c\u3042\u308a\u307e\u3059\u3002late\u306e\u4f7f\u3044\u65b9\u306b\u306f\uff12\u3064\u306e\u30b1\u30fc\u30b9\u304c\u3042\u308a\u307e\u3059\u3002<br \/>\n\u2460\u5f8c\u3067\u5024\u304c\u5165\u308b\u3053\u3068\u3092\u524d\u63d0\u3068\u3057\u305f\u5ba3\u8a00<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nlate String name; \/\/\u3053\u3053\u3067\u306f\u5024\u304c\u5165\u3063\u3066\u3044\u306a\u3044\u306e\u3067\u3001null\u306b\u306a\u3063\u3066\u3044\u308b\u3002\r\nvoid main() {\r\n  name = 'John';\u3000\/\/\u3053\u3053\u3067\u521d\u3081\u3066\u5024\u304c\u5165\u3063\u305f\u3002\r\n  print(name);\u3000\/\/null\u3067\u306f\u306a\u3044\u306e\u3067\u30a8\u30e9\u30fc\u306b\u306a\u3089\u306a\u3044\r\n}\r\n<\/code><\/pre>\n<\/div>\n<p>\u2461\u5b9f\u969b\u306b\u3001\u305d\u306e\u5909\u6570\u304c\u547c\u3073\u51fa\u3055\u308c\u308b\u307e\u3067\u5024\u304c\u5165\u3089\u306a\u3044\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nString myName() {\r\n  return 'John';\r\n}\r\n\r\nvoid main() {\r\n  late String name = myName();\u3000\/\/\u3053\u306e\u6bb5\u968e\u3067\u306fname\u306fnull\u72b6\u614b\u3002\u3067\u3082\u547c\u3073\u51fa\u3055\u308c\u3066\u3044\u306a\u3044\u306e\u3067\u5b9f\u5bb3\u306a\u3057\r\n  print(name);\u3000\/\/\u3053\u3053\u3067name\u304c\u547c\u3073\u51fa\u3055\u308c\u3066\u521d\u3081\u3066\u5024\u304c\u4ee3\u5165\u3055\u308c\u305f\uff08\u521d\u671f\u5316\u3055\u308c\u305f\uff09\u3002\r\n}\r\n<\/code><\/pre>\n<\/div>\n<\/li>\n<li>final<br \/>\nfinal\u306f\u5b9f\u884c\u6642\u306b\u5024\u304c\u5165\u308a\u3001\u305d\u306e\u5f8c\u3001\u5b9f\u884c\u4e2d\u306f\u5024\u304c\u5909\u308f\u3089\u306a\u3044\u5909\u6570\u306e\u3053\u3068\u3067\u3059\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nvoid main() {\r\n  final now = DateTime.now(); \/\/\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u5b9f\u884c\u3055\u308c\u6700\u521d\u306b\u547c\u3073\u51fa\u3055\u308c\u305f\u65e5\u6642\u304c\u4ee3\u5165\u3055\u308c\u308b\u3002\u30b3\u30f3\u30d1\u30a4\u30eb\u3055\u308c\u305f\u6642\u70b9\u3067\u306f\u672a\u5b9a\u3002\r\n  print(now);\r\n  now = DateTime.now(); \/\/\u3053\u3053\u3067\u30a8\u30e9\u30fc\u3068\u306a\u308b\u3002\r\n}\r\n\uff1d\u30a8\u30e9\u30fc\u30e1\u30c3\u30bb\u30fc\u30b8\uff1d\r\ncompileDDC\r\nmain.dart:4:10: Error: Expected ';' after this.\r\n  name = 'john'\r\n         ^^^^^^\r\nmain.dart:4:3: Error: Can't assign to the final variable 'name'.\r\n  name = 'john'\r\n  ^^^^\r\n<\/code><\/pre>\n<\/div>\n<\/li>\n<li>const<br \/>\nconst\u306f\u5b9a\u6570\u306a\u306e\u3067\u3001\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u5b9a\u7fa9\u3057\u305f\u5f8c\u306f\u5909\u308f\u308a\u307e\u305b\u3093\u3002<br \/>\n\u3067\u3059\u304c\u3001\u3053\u3093\u306a\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism line-numbers lang-dart\" data-lang=\"Dart\"><code>\r\nvoid main() {\r\n  var foo = const [];\r\n  print(foo);\u3000\/\/\u7a7a\u306e\u914d\u5217\u304c\u8868\u793a\r\n  foo = [3, 5, 4];\r\n  print(foo);\u3000\/\/[3, 5, 4]\u3068\u8868\u793a\u3055\u308c\u3001\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u305b\u3093\uff01\r\n  foo = [2, 4];\r\n  print(foo);\u3000\/\/[2, 4]\u3068\u8868\u793a\u3055\u308c\u3001\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u305b\u3093\uff01\r\n}\r\n\r\n<\/code><\/pre>\n<\/div>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>ChatGPT\u5148\u751f\u306b\u76e3\u4fee\u3057\u3066\u9802\u3044\u3066Dart\u306e\u5b66\u7fd2\u3092\u518d\u958b\u3057\u307e\u3059\u3002 \u3053\u308c\u307e\u3067\u306e\u8a18\u8ff0\u306b\u4e0d\u8db3\u3057\u3066\u3044\u305f\u3068\u3053\u308d\u3092\u9069\u5b9c\u304f\u308f\u3048\u3066\u3044\u304d\u307e\u3059\u3002\u4eca\u56de\u306f\u3001\u5909\u6570\u3068\u30c7\u30fc\u30bf\u578b\u3067\u3059\u3002 \u5909\u6570\u3068\u306f\u3001\u6570\u5024\u3084\u6587\u5b57\u5217\u7b49\u306e\u30c7\u30fc\u30bf\u3092\u4fdd\u5b58\u3057\u3066\u304a\u304f\u5165\u308c\u7269\u3067\u3001\u4f55\u3089\u304b\u306e\u540d\u524d&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[595,505],"tags":[601,619],"class_list":["post-4508","post","type-post","status-publish","format-standard","hentry","category-dart2","category-programming","tag-dart"],"_links":{"self":[{"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/posts\/4508","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4508"}],"version-history":[{"count":12,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/posts\/4508\/revisions"}],"predecessor-version":[{"id":4525,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=\/wp\/v2\/posts\/4508\/revisions\/4525"}],"wp:attachment":[{"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wsmeguro.jp\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}