{"id":11011,"date":"2022-11-23T16:06:15","date_gmt":"2022-11-23T07:06:15","guid":{"rendered":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/?p=11011"},"modified":"2022-11-23T16:06:15","modified_gmt":"2022-11-23T07:06:15","slug":"ts-array","status":"publish","type":"post","link":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/2022\/11\/23\/ts-array\/","title":{"rendered":"TypeScript \u914d\u5217\u307e\u3068\u3081"},"content":{"rendered":"

TypeScript\u306e\u914d\u5217\u306b\u3064\u3044\u3066\u3056\u3063\u3068\u307e\u3068\u3081\u307e\u3057\u305f\u3002<\/p>\n

\u57fa\u672c\u5f62<\/h2>\n

\u578b\u306e\u5f8c\u308d\u306b[]\u3092\u3064\u3051\u308b\u66f8\u304d\u65b9\u3068Array<T>\u3092\u7528\u3044\u308b\u66f8\u304d\u65b9\u304c\u3042\u308b\u3002\u3069\u3061\u3089\u3067\u3082OK\u3002<\/p>\n

\r\nlet array1: number[];\r\narray1 = [1, 2, 3];\r\nconsole.log(array1);\r\nlet array2: Array<number>;\r\narray2 = [1, 2, 3];\r\nconsole.log(array1);\r\n\/\/[ 1, 2, 3 ]\r\n\/\/[ 1, 2, 3 ]\r\n\u3000\r\n<\/pre>\n
 <\/p>\n
\u5b58\u5728\u3057\u306a\u3044\u8981\u7d20\u306b\u30a2\u30af\u30bb\u30b9\u3057\u305f\u6642\u306e\u6319\u52d5<\/h2>\n
\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u7279\u306b\u30a8\u30e9\u30fc\u306b\u306a\u308b\u3053\u3068\u306a\u304f\u300cundefined\u300d\u306b\u306a\u308b\u3002\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u304a\u3046\u3068\u3059\u308b\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308b\u305f\u3081\u3001typeof\u3067\u7d5e\u308a\u8fbc\u3080\u3053\u3068\u3067\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306f\u306a\u3089\u306a\u3044\u3002<\/p>\n
\r\nconst array = ["a", "b", "c"];\r\nconsole.log(array[100]);\r\n\/\/ undefined\r\n\r\narray[100].toUpperCase(); \/\/\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\r\n\r\nif (typeof array[100] === "string") {\r\n  array[100].toUpperCase(); \/\/\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u3089\u306a\u3044\r\n}\r\n \r\n<\/pre>\n
 <\/p>\n
\u8aad\u307f\u53d6\u308a\u5c02\u7528\u306e\u914d\u5217<\/h2>\n
\u914d\u5217\u306fconst\u5ba3\u8a00\u3057\u3066\u3082\u7de8\u96c6\u3067\u304d\u3066\u3057\u307e\u3046\u306e\u3067\u3001\u3082\u3057\u7de8\u96c6\u4e0d\u53ef\u306b\u3057\u305f\u3044\u5834\u5408\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u66f8\u304d\u65b9\u3092\u3059\u308b\u3002<\/p>\n
\r\nconst array1: readonly number[] = [1, 2, 3];\r\nconst array2: ReadonlyArray<number> = [1, 2, 3];\r\narray1.push(4); \/\/\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\r\n \r\n<\/pre>\n
 <\/p>\n
\u914d\u5217\u306e\u5206\u5272\u4ee3\u5165<\/h2>\n
\u914d\u5217\u306e\u8981\u7d20\u3092\u5909\u6570\u306b\u5206\u5272\u7de8\u96c6\u3059\u308b\u65b9\u6cd5\u3002\u8981\u7d20\u6570\u3092\u8d85\u3048\u3066\u3082\u30a8\u30e9\u30fc\u306b\u306f\u306a\u3089\u305aundefined\u306b\u306a\u308b\u3002<\/p>\n
\r\nconst num = [1, 2, 3];\r\nconst [num1, num2, num3, num4] = num;\r\nconsole.log(num1);\r\nconsole.log(num2);\r\nconsole.log(num3);\r\nconsole.log(num4);\r\n\/\/1\r\n\/\/2\r\n\/\/3\r\n\/\/undefined\r\n \r\n<\/pre>\n
 <\/p>\n
\u914d\u5217\u306e\u7e70\u308a\u8fd4\u3057\u51e6\u7406<\/h2>\n
\u914d\u5217\u306e\u7e70\u308a\u8fd4\u3057\u51e6\u7406\u306f\u4ee5\u4e0b\u306e\uff13\u30d1\u30bf\u30fc\u30f3\u3002<\/p>\n
\r\nconst array = ["a", "b", "c", "d"];\r\nfor(let i = 0; i < array.length; i++) {\r\n  console.log(i, array[i]);\r\n}\r\nfor(const value of array) {\r\n  console.log(value);\r\n}\r\narray.forEach((value, i) => {\r\n  console.log(i, value);\r\n});\r\n\u3000\r\n<\/pre>\n
 <\/p>\n","protected":false},"excerpt":{"rendered":"
TypeScript\u306e\u914d\u5217\u306b\u3064\u3044\u3066\u3056\u3063\u3068\u307e\u3068\u3081\u307e\u3057\u305f\u3002 \u57fa\u672c\u5f62 \u578b\u306e\u5f8c\u308d\u306b[]\u3092 … <\/p>\n","protected":false},"author":1,"featured_media":11014,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[59],"tags":[],"class_list":["post-11011","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-typescript"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/posts\/11011","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/comments?post=11011"}],"version-history":[{"count":3,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/posts\/11011\/revisions"}],"predecessor-version":[{"id":11015,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/posts\/11011\/revisions\/11015"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/media\/11014"}],"wp:attachment":[{"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/media?parent=11011"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/categories?post=11011"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pineplanter.moo.jp\/non-it-salaryman\/wp-json\/wp\/v2\/tags?post=11011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}