{"id":5264,"date":"2023-01-05T12:20:09","date_gmt":"2023-01-05T04:20:09","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=5264"},"modified":"2023-01-05T12:20:09","modified_gmt":"2023-01-05T04:20:09","slug":"%e5%ad%b8%e7%bf%92typescript%e4%b8%ad%e7%9a%84%e6%95%b8%e7%b5%84%e6%b1%82%e5%8d%94%e6%96%b9%e5%b7%ae","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/typescript\/%e5%ad%b8%e7%bf%92typescript%e4%b8%ad%e7%9a%84%e6%95%b8%e7%b5%84%e6%b1%82%e5%8d%94%e6%96%b9%e5%b7%ae\/","title":{"rendered":"\u5b78\u7fd2TypeScript\u4e2d\u7684\u6578\u7d44\u6c42\u5354\u65b9\u5dee"},"content":{"rendered":"<p><meta name=\"keywords\" content=\"TypeScript, \u6578\u7d44, \u5354\u65b9\u5dee, Array Covariance\"><\/p>\n<h1>TypeScript \u6578\u7d44\u7684\u6c42\u5354\u65b9\u5dee(Array Covariance)<\/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\u6642\u66f4\u52a0\u5b89\u5168\u53ef\u9760\u3002\u5728 TypeScript \u4e2d\uff0c\u6578\u7d44\u53ef\u4ee5\u88ab\u5b9a\u7fa9\u70ba\u4e00\u7a2e\u7279\u6b8a\u7684\u985e\u578b\uff0c\u53ef\u4ee5\u7528\u4f86\u5b58\u5132\u4e00\u7cfb\u5217\u7684\u503c\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u5c07\u8a0e\u8ad6 TypeScript \u4e2d\u7684\u6578\u7d44\u5354\u65b9\u5dee\uff0c\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4f86\u6c42\u53d6\u6578\u7d44\u7684\u5354\u65b9\u5dee\u3002<\/p>\n<h2>\u4ec0\u9ebc\u662f\u6578\u7d44\u5354\u65b9\u5dee\uff1f<\/h2>\n<p>\u6578\u7d44\u5354\u65b9\u5dee\u662f\u4e00\u7a2e\u7d71\u8a08\u6982\u5ff5\uff0c\u7528\u65bc\u8861\u91cf\u5169\u500b\u6578\u7d44\u4e4b\u9593\u7684\u95dc\u4fc2\u3002\u5b83\u53ef\u4ee5\u7528\u4f86\u8861\u91cf\u5169\u500b\u6578\u7d44\u4e4b\u9593\u7684\u76f8\u95dc\u6027\uff0c\u4ee5\u53ca\u5169\u500b\u6578\u7d44\u4e4b\u9593\u7684\u8b8a\u5316\u7a0b\u5ea6\u3002\u6578\u7d44\u5354\u65b9\u5dee\u7684\u503c\u53ef\u4ee5\u5728 -1 \u5230 1 \u4e4b\u9593\uff0c\u5176\u4e2d -1 \u8868\u793a\u5b8c\u5168\u8ca0\u76f8\u95dc\uff0c1 \u8868\u793a\u5b8c\u5168\u6b63\u76f8\u95dc\uff0c0 \u8868\u793a\u6c92\u6709\u76f8\u95dc\u6027\u3002<\/p>\n<h2>\u5982\u4f55\u4f7f\u7528 TypeScript \u6c42\u53d6\u6578\u7d44\u5354\u65b9\u5dee\uff1f<\/h2>\n<p>\u5728 TypeScript \u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528 Array.prototype.reduce() \u65b9\u6cd5\u4f86\u6c42\u53d6\u6578\u7d44\u5354\u65b9\u5dee\u3002Array.prototype.reduce() \u65b9\u6cd5\u53ef\u4ee5\u5c0d\u6578\u7d44\u4e2d\u7684\u6bcf\u500b\u5143\u7d20\u57f7\u884c\u4e00\u500b\u6307\u5b9a\u7684\u51fd\u6578\uff0c\u4e26\u5c07\u51fd\u6578\u7684\u7d50\u679c\u7d2f\u52a0\u8d77\u4f86\uff0c\u6700\u5f8c\u8fd4\u56de\u4e00\u500b\u7d2f\u52a0\u7d50\u679c\u3002<\/p>\n<pre class=\"brush: javascript\">\n\/\/ \u5b9a\u7fa9\u5169\u500b\u6578\u7d44\nlet arr1 = [1, 2, 3, 4, 5];\nlet arr2 = [2, 4, 6, 8, 10];\n\n\/\/ \u4f7f\u7528 Array.prototype.reduce() \u65b9\u6cd5\u6c42\u53d6\u6578\u7d44\u5354\u65b9\u5dee\nlet covariance = arr1.reduce((acc, cur, i) => {\n  return acc + (cur - arr1.reduce((a, c) => a + c, 0) \/ arr1.length) * (arr2[i] - arr2.reduce((a, c) => a + c, 0) \/ arr2.length);\n}, 0);\n\n\/\/ \u8f38\u51fa\u7d50\u679c\nconsole.log(covariance); \/\/ 8\n<\/pre>\n<p>\u4e0a\u9762\u7684\u7a0b\u5f0f\u78bc\u4e2d\uff0c\u6211\u5011\u4f7f\u7528 Array.prototype.reduce() \u65b9\u6cd5\u5c0d\u5169\u500b\u6578\u7d44\u4e2d\u7684\u6bcf\u500b\u5143\u7d20\u57f7\u884c\u4e00\u500b\u6307\u5b9a\u7684\u51fd\u6578\uff0c\u4e26\u5c07\u51fd\u6578\u7684\u7d50\u679c\u7d2f\u52a0\u8d77\u4f86\uff0c\u6700\u5f8c\u8fd4\u56de\u4e00\u500b\u7d2f\u52a0\u7d50\u679c\uff0c\u5373\u6578\u7d44\u5354\u65b9\u5dee\u7684\u503c\u3002<\/p>\n<p><!--more--><\/p>\n<h2>\u7e3d\u7d50<\/h2>\n<p>\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u8a0e\u8ad6\u4e86 TypeScript \u4e2d\u7684\u6578\u7d44\u5354\u65b9\u5dee\uff0c\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528 Array.prototype.reduce() \u65b9\u6cd5\u4f86\u6c42\u53d6\u6578\u7d44\u5354\u65b9\u5dee\u3002\u6578\u7d44\u5354\u65b9\u5dee\u53ef\u4ee5\u7528\u4f86\u8861\u91cf\u5169\u500b\u6578\u7d44\u4e4b\u9593\u7684\u76f8\u95dc\u6027\uff0c\u4ee5\u53ca\u5169\u500b\u6578\u7d44\u4e4b\u9593\u7684\u8b8a\u5316\u7a0b\u5ea6\u3002\u4f7f\u7528 Array.prototype.reduce() \u65b9\u6cd5\u53ef\u4ee5\u8f15\u9b06\u6c42\u53d6\u6578\u7d44\u5354\u65b9\u5dee\uff0c\u4e26\u5c07\u7d50\u679c\u8f38\u51fa\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6587\u7ae0\u6458\u8981\uff1a\u672c\u6587\u5c07\u4ecb\u7d39TypeScript\u4e2d\u7684\u6578\u7d44\u6c42\u5354\u65b9\u5dee\uff0c\u8a73\u7d30\u89e3\u91cb\u5982\u4f55\u4f7f\u7528TypeScript\u4e2d\u7684\u51fd\u6578\u4f86\u8a08\u7b97\u6578\u7d44\u7684\u5354\u65b9\u5dee\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u793a\u4f8b\u4f86\u8a73\u7d30\u8aaa\u660e\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-5264","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\/pcFK27-1mU","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/5264","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=5264"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/5264\/revisions"}],"predecessor-version":[{"id":5265,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/5264\/revisions\/5265"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=5264"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=5264"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=5264"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}