{"id":4878,"date":"2023-01-05T11:11:42","date_gmt":"2023-01-05T03:11:42","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=4878"},"modified":"2023-01-05T11:11:42","modified_gmt":"2023-01-05T03:11:42","slug":"%e5%ad%b8%e7%bf%92%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8typescript%e7%b1%bb%e5%9e%8b%e8%bd%ac%e6%8d%a2%e5%87%bd%e6%95%b0typeassertions-2","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/typescript\/%e5%ad%b8%e7%bf%92%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8typescript%e7%b1%bb%e5%9e%8b%e8%bd%ac%e6%8d%a2%e5%87%bd%e6%95%b0typeassertions-2\/","title":{"rendered":"\u5b78\u7fd2\u5982\u4f55\u4f7f\u7528TypeScript\u7c7b\u578b\u8f6c\u6362\u51fd\u6570(typeassertions)"},"content":{"rendered":"

<\/p>\n

TypeScript \u7c7b\u578b\u8f6c\u6362\u51fd\u6570(type assertions)\u7684\u8a9e\u6cd5<\/h1>\n

TypeScript \u662f\u4e00\u7a2e\u7531 Microsoft \u958b\u767c\u7684 JavaScript \u7684\u8d85\u96c6\uff0c\u5b83\u63d0\u4f9b\u4e86\u985e\u578b\u6aa2\u67e5\u548c\u985e\u578b\u8f49\u63db\u7684\u529f\u80fd\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7ba1\u7406\u7a0b\u5f0f\u78bc\u3002\u5176\u4e2d\uff0cTypeScript \u7684\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\uff08type assertions\uff09\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5c07\u4e00\u500b\u8b8a\u91cf\u7684\u985e\u578b\u5f9e\u4e00\u7a2e\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u985e\u578b\uff0c\u4ee5\u6eff\u8db3\u7a0b\u5f0f\u78bc\u7684\u9700\u6c42\u3002<\/p>\n

TypeScript \u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u7684\u8a9e\u6cd5<\/h2>\n

TypeScript \u7684\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u7684\u8a9e\u6cd5\u975e\u5e38\u7c21\u55ae\uff0c\u53ea\u9700\u8981\u5728\u8b8a\u91cf\u524d\u9762\u52a0\u4e0a as<\/code> \u95dc\u9375\u5b57\uff0c\u7136\u5f8c\u6307\u5b9a\u8981\u8f49\u63db\u7684\u985e\u578b\u5373\u53ef\u3002\u4f8b\u5982\uff0c\u5c07\u4e00\u500b string<\/code> \u8b8a\u91cf\u8f49\u63db\u70ba number<\/code> \u985e\u578b\uff1a<\/p>\n

\nlet str: string = \"123\";\nlet num: number = str as number;\n<\/pre>\n
\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0c\u6211\u5011\u5c07 str<\/code> \u8b8a\u91cf\u7684\u985e\u578b\u5f9e string<\/code> \u8f49\u63db\u70ba number<\/code>\uff0c\u4e26\u5c07\u8f49\u63db\u5f8c\u7684\u7d50\u679c\u8ce6\u503c\u7d66 num<\/code> \u8b8a\u91cf\u3002<\/p>\n
TypeScript \u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u7684\u512a\u9ede<\/h2>\n
TypeScript \u7684\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7ba1\u7406\u7a0b\u5f0f\u78bc\uff0c\u4e26\u6e1b\u5c11\u7a0b\u5f0f\u78bc\u51fa\u932f\u7684\u6a5f\u6703\u3002\u6b64\u5916\uff0c\u5b83\u9084\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7406\u89e3\u7a0b\u5f0f\u78bc\uff0c\u56e0\u70ba\u5b83\u53ef\u4ee5\u6e05\u695a\u5730\u8868\u660e\u8b8a\u91cf\u7684\u985e\u578b\uff0c\u4ee5\u53ca\u8b8a\u91cf\u7684\u503c\u662f\u5982\u4f55\u8f49\u63db\u7684\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
TypeScript \u7684\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7ba1\u7406\u7a0b\u5f0f\u78bc\uff0c\u4e26\u6e1b\u5c11\u7a0b\u5f0f\u78bc\u51fa\u932f\u7684\u6a5f\u6703\u3002\u5b83\u7684\u8a9e\u6cd5\u975e\u5e38\u7c21\u55ae\uff0c\u53ea\u9700\u8981\u5728\u8b8a\u91cf\u524d\u9762\u52a0\u4e0a as<\/code> \u95dc\u9375\u5b57\uff0c\u7136\u5f8c\u6307\u5b9a\u8981\u8f49\u63db\u7684\u985e\u578b\u5373\u53ef\u3002TypeScript \u7684\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7406\u89e3\u7a0b\u5f0f\u78bc\uff0c\u4e26\u6e1b\u5c11\u7a0b\u5f0f\u78bc\u51fa\u932f\u7684\u6a5f\u6703\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6458\u8981\uff1aTypeScript\u7c7b\u578b\u8f6c\u6362\u51fd\u6570(typeassertions)\u662f\u4e00\u79cd\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u8ba9\u4f60\u5728TypeScript\u4e2d\u66f4\u6709\u6548\u5730\u4f7f\u7528\u7c7b\u578b\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u5982\u4f55\u4f7f\u7528TypeScript\u7c7b\u578b\u8f6c\u6362\u51fd\u6570\uff0c\u4ee5\u53ca\u5b83\u7684\u512a\u9ede\u548c\u7f3a\u9ede\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-4878","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\/pcFK27-1gG","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4878","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=4878"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4878\/revisions"}],"predecessor-version":[{"id":4879,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4878\/revisions\/4879"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=4878"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=4878"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=4878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}