{"id":4838,"date":"2023-01-05T10:43:54","date_gmt":"2023-01-05T02:43:54","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=4838"},"modified":"2023-01-05T10:43:54","modified_gmt":"2023-01-05T02:43:54","slug":"%e4%ba%86%e8%a7%a3typescript%e5%ad%97%e9%9d%a2%e9%87%8f%e9%a1%9e%e5%9e%8b%e7%9a%84%e5%a8%81%e5%8a%9b","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/typescript\/%e4%ba%86%e8%a7%a3typescript%e5%ad%97%e9%9d%a2%e9%87%8f%e9%a1%9e%e5%9e%8b%e7%9a%84%e5%a8%81%e5%8a%9b\/","title":{"rendered":"\u4e86\u89e3TypeScript\u5b57\u9762\u91cf\u985e\u578b\u7684\u5a01\u529b"},"content":{"rendered":"<p><meta name=\"keywords\" content=\"TypeScript, \u5b57\u9762\u91cf\u7c7b\u578b, literal type\"><\/p>\n<h1>TypeScript \u5b57\u9762\u91cf\u7c7b\u578b(literal type)<\/h1>\n<p>TypeScript \u662f\u4e00\u7a2e JavaScript \u7684\u8d85\u96c6\uff0c\u5b83\u63d0\u4f9b\u4e86\u985e\u578b\u7cfb\u7d71\uff0c\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5728\u7de8\u5beb\u7a0b\u5f0f\u78bc\u6642\u66f4\u52a0\u5b89\u5168\u53ef\u9760\u3002\u5176\u4e2d\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\u5c31\u662f\u300c\u5b57\u9762\u91cf\u7c7b\u578b(literal type)\u300d\uff0c\u5b83\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u66f4\u52a0\u7cbe\u78ba\u5730\u6307\u5b9a\u8b8a\u6578\u7684\u578b\u5225\uff0c\u4ee5\u53ca\u66f4\u52a0\u5b89\u5168\u5730\u4f7f\u7528\u8b8a\u6578\u3002<\/p>\n<p><!--more--><\/p>\n<p>\u5b57\u9762\u91cf\u7c7b\u578b\u662f\u6307\u4e00\u500b\u8b8a\u6578\u53ea\u80fd\u63a5\u53d7\u7279\u5b9a\u7684\u503c\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre class=\"brush: typescript\">\nlet myNumber: 1 | 2 | 3;\nmyNumber = 1; \/\/ OK\nmyNumber = 4; \/\/ Error\n<\/pre>\n<p>\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0c\u6211\u5011\u5b9a\u7fa9\u4e86\u4e00\u500b\u8b8a\u6578 <code>myNumber<\/code>\uff0c\u5b83\u7684\u578b\u5225\u662f <code>1 | 2 | 3<\/code>\uff0c\u4e5f\u5c31\u662f\u8aaa\u5b83\u53ea\u80fd\u63a5\u53d7 <code>1<\/code>\u3001<code>2<\/code> \u6216 <code>3<\/code> \u9019\u4e09\u500b\u503c\u3002<\/p>\n<p>\u5b57\u9762\u91cf\u7c7b\u578b\u53ef\u4ee5\u7528\u65bc\u4efb\u4f55\u578b\u5225\uff0c\u4f8b\u5982\u5b57\u4e32\uff1a<\/p>\n<pre class=\"brush: typescript\">\nlet myString: \"foo\" | \"bar\";\nmyString = \"foo\"; \/\/ OK\nmyString = \"baz\"; \/\/ Error\n<\/pre>\n<p>\u5b57\u9762\u91cf\u7c7b\u578b\u53ef\u4ee5\u7528\u65bc\u4efb\u4f55\u578b\u5225\uff0c\u5305\u62ec\u8907\u5408\u578b\u5225\uff1a<\/p>\n<pre class=\"brush: typescript\">\ntype MyType = {\n  foo: \"foo\" | \"bar\";\n  bar: number;\n};\n\nlet myObject: MyType = {\n  foo: \"foo\",\n  bar: 1\n};\n\nmyObject = {\n  foo: \"baz\",\n  bar: 2\n}; \/\/ Error\n<\/pre>\n<p>\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0c\u6211\u5011\u5b9a\u7fa9\u4e86\u4e00\u500b\u8907\u5408\u578b\u5225 <code>MyType<\/code>\uff0c\u5b83\u6709\u5169\u500b\u5c6c\u6027\uff1a<code>foo<\/code> \u548c <code>bar<\/code>\uff0c\u5176\u4e2d <code>foo<\/code> \u7684\u578b\u5225\u662f <code>\"foo\" | \"bar\"<\/code>\uff0c\u4e5f\u5c31\u662f\u53ea\u80fd\u63a5\u53d7 <code>\"foo\"<\/code> \u6216 <code>\"bar\"<\/code> \u9019\u5169\u500b\u503c\u3002<\/p>\n<p>\u5b57\u9762\u91cf\u7c7b\u578b\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u66f4\u52a0\u7cbe\u78ba\u5730\u6307\u5b9a\u8b8a\u6578\u7684\u578b\u5225\uff0c\u4ee5\u53ca\u66f4\u52a0\u5b89\u5168\u5730\u4f7f\u7528\u8b8a\u6578\uff0c\u56e0\u6b64\u5728\u958b\u767c TypeScript \u61c9\u7528\u7a0b\u5f0f\u6642\uff0c\u61c9\u8a72\u591a\u52a0\u5229\u7528\u5b57\u9762\u91cf\u7c7b\u578b\uff0c\u4ee5\u63d0\u9ad8\u7a0b\u5f0f\u78bc\u7684\u54c1\u8cea\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3TypeScript\u5b57\u9762\u91cf\u985e\u578b\u7684\u5a01\u529b\uff0c\u5b83\u53ef\u4ee5\u8b93\u4f60\u66f4\u6709\u6548\u7387\u5730\u958b\u767c\u51fa\u66f4\u56b4\u8b39\u7684\u7a0b\u5f0f\u78bc\uff0c\u66f4\u5bb9\u6613\u5730\u638c\u63e1\u7a0b\u5f0f\u78bc\u7684\u7d30\u7bc0\uff0c\u4e26\u4e14\u66f4\u5bb9\u6613\u5730\u638c\u63e1\u7a0b\u5f0f\u78bc\u7684\u7d30\u7bc0\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[187],"tags":[186],"class_list":["post-4838","post","type-post","status-publish","format-standard","hentry","category-typescript","tag-typescript"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_shortlink":"https:\/\/wp.me\/pcFK27-1g2","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4838","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/comments?post=4838"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4838\/revisions"}],"predecessor-version":[{"id":4839,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4838\/revisions\/4839"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=4838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=4838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=4838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}