{"id":34169,"date":"2023-03-02T14:30:38","date_gmt":"2023-03-02T09:00:38","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/"},"modified":"2023-03-02T14:30:38","modified_gmt":"2023-03-02T09:00:38","slug":"solved-why-does-aad-match-the-string-ad-duplicate","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/","title":{"rendered":"[Solved] Why does a*ad$ match the string “ad”? [duplicate]"},"content":{"rendered":"

[ad_1]
\n<\/p>\n

\n
\n
<\/div>\n
\n
\n
\n

Shouldn’t the a*<\/code> match with the a<\/code> in the string?<\/p>\n<\/blockquote>\n

No, because *<\/code> means a<\/code> can match zero<\/em> or more times, so the ''<\/code> empty string<\/em> also matches that expression. That leaves 'ad'<\/code> after the initial empty string to match for the remainder of the expression.<\/p>\n

A regex will consider both options here (both ''<\/code>, the empty string, and 'a'<\/code> satisfy the a*<\/code> pattern).<\/p>\n

Use a+<\/code> if you wanted the pattern to match at least once<\/em>.<\/p>\n<\/p><\/div>\n

<\/div>\n<\/div>\n

2<\/span> <\/p><\/div>\n<\/div>\n

[ad_2]<\/p>\n

solved Why does a*ad$ match the string “ad”? [duplicate] <\/p>\n","protected":false},"excerpt":{"rendered":"

[ad_1] Shouldn’t the a* match with the a in the string? No, because * means a can match zero or more times, so the ” empty string also matches that expression. That leaves ‘ad’ after the initial empty string to match for the remainder of the expression. A regex will consider both options here (both … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[349,347],"class_list":["post-34169","post","type-post","status-publish","format-standard","hentry","category-solved","tag-python","tag-regex"],"yoast_head":"\n[Solved] Why does a*ad$ match the string "ad"? [duplicate] - JassWeb<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] Why does a*ad$ match the string "ad"? [duplicate] - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] Shouldn’t the a* match with the a in the string? No, because * means a can match zero or more times, so the '' empty string also matches that expression. That leaves 'ad' after the initial empty string to match for the remainder of the expression. A regex will consider both options here (both ... Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\" \/>\n<meta property=\"og:site_name\" content=\"JassWeb\" \/>\n<meta property=\"article:published_time\" content=\"2023-03-02T09:00:38+00:00\" \/>\n<meta name=\"author\" content=\"Kirat\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Kirat\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\"},\"author\":{\"name\":\"Kirat\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\"},\"headline\":\"[Solved] Why does a*ad$ match the string “ad”? [duplicate]\",\"datePublished\":\"2023-03-02T09:00:38+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\"},\"wordCount\":89,\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"keywords\":[\"python\",\"regex\"],\"articleSection\":[\"Solved\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\",\"url\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\",\"name\":\"[Solved] Why does a*ad$ match the string \\\"ad\\\"? [duplicate] - JassWeb\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#website\"},\"datePublished\":\"2023-03-02T09:00:38+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/jassweb.com\/solved\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"[Solved] Why does a*ad$ match the string “ad”? [duplicate]\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/jassweb.com\/solved\/#website\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"name\":\"JassWeb\",\"description\":\"Build High-quality Websites\",\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/jassweb.com\/solved\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\",\"name\":\"Jass Web\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"contentUrl\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"width\":693,\"height\":132,\"caption\":\"Jass Web\"},\"image\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\",\"name\":\"Kirat\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"contentUrl\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"caption\":\"Kirat\"},\"sameAs\":[\"http:\/\/jassweb.com\"],\"url\":\"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"[Solved] Why does a*ad$ match the string \"ad\"? [duplicate] - JassWeb","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/","og_locale":"en_US","og_type":"article","og_title":"[Solved] Why does a*ad$ match the string \"ad\"? [duplicate] - JassWeb","og_description":"[ad_1] Shouldn’t the a* match with the a in the string? No, because * means a can match zero or more times, so the '' empty string also matches that expression. That leaves 'ad' after the initial empty string to match for the remainder of the expression. A regex will consider both options here (both ... Read more","og_url":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/","og_site_name":"JassWeb","article_published_time":"2023-03-02T09:00:38+00:00","author":"Kirat","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Kirat"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#article","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/"},"author":{"name":"Kirat","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31"},"headline":"[Solved] Why does a*ad$ match the string “ad”? [duplicate]","datePublished":"2023-03-02T09:00:38+00:00","mainEntityOfPage":{"@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/"},"wordCount":89,"publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"keywords":["python","regex"],"articleSection":["Solved"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/","url":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/","name":"[Solved] Why does a*ad$ match the string \"ad\"? [duplicate] - JassWeb","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/#website"},"datePublished":"2023-03-02T09:00:38+00:00","breadcrumb":{"@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/jassweb.com\/solved\/solved-why-does-aad-match-the-string-ad-duplicate\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/jassweb.com\/solved\/"},{"@type":"ListItem","position":2,"name":"[Solved] Why does a*ad$ match the string “ad”? [duplicate]"}]},{"@type":"WebSite","@id":"https:\/\/jassweb.com\/solved\/#website","url":"https:\/\/jassweb.com\/solved\/","name":"JassWeb","description":"Build High-quality Websites","publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/jassweb.com\/solved\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/jassweb.com\/solved\/#organization","name":"Jass Web","url":"https:\/\/jassweb.com\/solved\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/","url":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","contentUrl":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","width":693,"height":132,"caption":"Jass Web"},"image":{"@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31","name":"Kirat","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/","url":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","contentUrl":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","caption":"Kirat"},"sameAs":["http:\/\/jassweb.com"],"url":"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/"}]}},"_links":{"self":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/34169","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/comments?post=34169"}],"version-history":[{"count":0,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/34169\/revisions"}],"wp:attachment":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/media?parent=34169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/categories?post=34169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/tags?post=34169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}