{"id":4908,"date":"2023-01-05T11:17:02","date_gmt":"2023-01-05T03:17:02","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=4908"},"modified":"2023-01-05T11:17:02","modified_gmt":"2023-01-05T03:17:02","slug":"%e4%ba%86%e8%a7%a3typescript%e4%b8%ad%e7%9a%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e5%8a%9f%e8%83%bd","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/typescript\/%e4%ba%86%e8%a7%a3typescript%e4%b8%ad%e7%9a%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e5%8a%9f%e8%83%bd\/","title":{"rendered":"\u4e86\u89e3TypeScript\u4e2d\u7684\u985e\u578b\u8f49\u63db\u529f\u80fd"},"content":{"rendered":"

<\/p>\n

TypeScript \u985e\u578b\u8f49\u63db (Type Casting)<\/h1>\n

TypeScript \u662f\u4e00\u7a2e JavaScript \u7684\u8d85\u96c6\uff0c\u5b83\u63d0\u4f9b\u4e86\u985e\u578b\u8f49\u63db (Type Casting) \u7684\u529f\u80fd\uff0c\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5728\u7de8\u5beb\u7a0b\u5f0f\u6642\u66f4\u52a0\u5b89\u5168\u53ca\u6709\u6548\u7387\u3002<\/p>\n

<\/p>\n

\u985e\u578b\u8f49\u63db (Type Casting) \u662f\u6307\u5c07\u4e00\u500b\u8b8a\u6578\u7684\u985e\u578b\u5f9e\u4e00\u500b\u985e\u578b\u8f49\u63db\u6210\u53e6\u4e00\u500b\u985e\u578b\uff0c\u4f8b\u5982\u5c07\u4e00\u500b string<\/span> \u8f49\u63db\u6210 number<\/span>\u3002<\/p>\n

TypeScript \u63d0\u4f9b\u4e86\u5169\u7a2e\u985e\u578b\u8f49\u63db\u7684\u65b9\u5f0f\uff1aimplicit<\/span> \u548c explicit<\/span>\u3002<\/p>\n

Implicit \u985e\u578b\u8f49\u63db<\/h2>\n

Implicit \u985e\u578b\u8f49\u63db\u662f\u6307 TypeScript \u6703\u81ea\u52d5\u5c07\u4e00\u500b\u8b8a\u6578\u7684\u985e\u578b\u5f9e\u4e00\u500b\u985e\u578b\u8f49\u63db\u6210\u53e6\u4e00\u500b\u985e\u578b\uff0c\u4f8b\u5982\uff1a<\/p>\n

\nlet a = \"123\";\nlet b = a * 1;\nconsole.log(b); \/\/ 123\n<\/pre>\n
\u5728\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0ca \u7684\u985e\u578b\u662f string<\/span>\uff0c\u4f46\u662f\u7576 a \u88ab\u4e58\u4ee5 1 \u6642\uff0cTypeScript \u6703\u81ea\u52d5\u5c07 a \u7684\u985e\u578b\u8f49\u63db\u6210 number<\/span>\uff0c\u6240\u4ee5 b \u7684\u985e\u578b\u4e5f\u6703\u88ab\u8f49\u63db\u6210 number<\/span>\u3002<\/p>\n
Explicit \u985e\u578b\u8f49\u63db<\/h2>\n
Explicit \u985e\u578b\u8f49\u63db\u662f\u6307\u958b\u767c\u8005\u53ef\u4ee5\u660e\u78ba\u7684\u6307\u5b9a\u4e00\u500b\u8b8a\u6578\u7684\u985e\u578b\uff0c\u4f8b\u5982\uff1a<\/p>\n
\nlet a = \"123\";\nlet b = Number<\/span>(a);\nconsole.log(b); \/\/ 123\n<\/pre>\n
\u5728\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0ca \u7684\u985e\u578b\u662f string<\/span>\uff0c\u4f46\u662f\u7576 a \u88ab Number<\/span> \u51fd\u5f0f\u8f49\u63db\u6642\uff0cTypeScript \u6703\u5c07 a \u7684\u985e\u578b\u8f49\u63db\u6210 number<\/span>\uff0c\u6240\u4ee5 b \u7684\u985e\u578b\u4e5f\u6703\u88ab\u8f49\u63db\u6210 number<\/span>\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
TypeScript \u63d0\u4f9b\u4e86\u985e\u578b\u8f49\u63db (Type Casting) \u7684\u529f\u80fd\uff0c\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5728\u7de8\u5beb\u7a0b\u5f0f\u6642\u66f4\u52a0\u5b89\u5168\u53ca\u6709\u6548\u7387\u3002TypeScript \u63d0\u4f9b\u4e86\u5169\u7a2e\u985e\u578b\u8f49\u63db\u7684\u65b9\u5f0f\uff1aImplicit \u985e\u578b\u8f49\u63db\u548c Explicit \u985e\u578b\u8f49\u63db\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6839\u64da\u81ea\u5df1\u7684\u9700\u6c42\u4f86\u9078\u64c7\u5408\u9069\u7684\u985e\u578b\u8f49\u63db\u65b9\u5f0f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6458\u8981:TypeScript\u662f\u4e00\u7a2e\u5f37\u578b\u5225\u7684JavaScript\u8173\u672c\u8a9e\u8a00\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u7a2e\u985e\u578b\u8f49\u63db\u7684\u529f\u80fd\uff0c\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5c07\u8cc7\u6599\u578b\u5225\u5f9e\u4e00\u7a2e\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\uff0c\u4ee5\u6eff\u8db3\u61c9\u7528\u7a0b\u5f0f\u7684\u9700\u6c42\u3002\u672c\u6587\u5c07\u4ecb\u7d39TypeScript\u4e2d\u7684\u985e\u578b\u8f49\u63db\u529f\u80fd\uff0c\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4f86\u63d0\u9ad8\u61c9\u7528\u7a0b\u5f0f\u7684\u6548\u7387\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-4908","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\/pcFK27-1ha","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4908","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=4908"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4908\/revisions"}],"predecessor-version":[{"id":4909,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4908\/revisions\/4909"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=4908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=4908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=4908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}