{"id":1972,"date":"2023-03-18T20:33:51","date_gmt":"2023-03-19T00:33:51","guid":{"rendered":"https:\/\/www.a2life.info\/w\/?p=1972"},"modified":"2025-09-27T13:10:15","modified_gmt":"2025-09-27T17:10:15","slug":"array_reduce%e3%81%ae%e8%a9%b1%ef%bc%92","status":"publish","type":"post","link":"https:\/\/www.a2life.info\/w\/?p=1972","title":{"rendered":"array_reduce\u306e\u8a71\uff12"},"content":{"rendered":"<p>array_reduce\u3068\u3000array\u306esplat\u3000\u30aa\u30da\u30ec\u30fc\u30bf\u30fc\u3092\u4f7f\u3046\u3068\u3001\u540c\u3058\u30a2\u30ec\u30fc\u3092\u751f\u6210\u3059\u308b\u3068\u3044\u3046\u610f\u5473\u306e\u306a\u3044\u95a2\u6570\u304c\u3067\u304d\u308b\u3002<\/p>\n\n\n<pre class=\"wp-block-code has-light-gray-color has-black-background-color has-text-color has-background has-link-color wp-elements-7463b64dc21566d103026c65f74cebba\"><code lang=\"php\" class=\"language-php\">\n$source_array=[3,2,4,5];\n$nop_array=array_reduce($source_array, fn($carry,$item)=&gt;[...$carry, $item],[]);\nprint_r($nop_array); \/\/array=&gt;[3,2,4,5]\n<\/code><\/pre>\n\n\n<p>\u3067\u3001\u30d1\u30bf\u30fc\u30f3\u3092\u4f7f\u3063\u3066\u3001array_map\u3082array_filter\u3082array_reduce\u3067\u4ee3\u7528\u3067\u304d\u308b\u3068\u3044\u3046\u304a\u8a71<\/p>\n\n\n<pre class=\"wp-block-code has-light-gray-color has-dark-gray-background-color has-text-color has-background has-link-color wp-elements-376c700297725dbb42bde3a86550c771\"><code lang=\"php\" class=\"language-php\">\n\n\n\/\/ array reduce to mimic array_map\n$source_array=[3,2,4,5];\n$double=function($x){\n    return $x*2;\n};\n$mapped_array=array_reduce($source_array,fn($carry,$item)=&gt;[...$carry,$double($item)],[]);\n\nprint_r($mapped_array); \/\/array=&gt;[6,4,8,10]\n\n\/\/array reduce to mimic array_filter\n\n$even_fn= function($x){ \/\/return true if even\n   return ($x % 2)==0;\n};\n\n\n$filtered_array=array_reduce($source_array,\n    fn($carry,$item)=&gt;$even_fn($item)?[...$carry,$item]:$carry,\n    []);\n\n\nprint_r($filtered_array); \/\/array=&gt;[2,4]\n\n<\/code><\/pre>\n\n\n<p>\u3081\u3067\u305f\u3057\u3001\u3081\u3067\u305f\u3057<\/p>","protected":false},"excerpt":{"rendered":"<p>array_reduce\u3068\u3000array\u306esplat\u3000\u30aa\u30da\u30ec\u30fc\u30bf\u30fc\u3092\u4f7f\u3046\u3068\u3001\u540c\u3058\u30a2\u30ec\u30fc\u3092\u751f\u6210\u3059\u308b\u3068\u3044\u3046\u610f\u5473\u306e\u306a\u3044\u95a2\u6570\u304c\u3067\u304d\u308b\u3002 \u3067\u3001\u30d1\u30bf\u30fc\u30f3\u3092\u4f7f\u3063\u3066\u3001array_map\u3082array_filter\u3082array_reduce\u3067\u4ee3\u7528\u3067\u304d\u308b\u3068\u3044\u3046\u304a\u8a71 \u3081\u3067\u305f\u3057\u3001\u3081\u3067\u305f\u3057<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29,3],"tags":[69],"class_list":["post-1972","post","type-post","status-publish","format-standard","hentry","category-php","category-web-making","tag-php"],"_links":{"self":[{"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/posts\/1972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1972"}],"version-history":[{"count":8,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/posts\/1972\/revisions"}],"predecessor-version":[{"id":2183,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=\/wp\/v2\/posts\/1972\/revisions\/2183"}],"wp:attachment":[{"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1972"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1972"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.a2life.info\/w\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}