{"id":158,"date":"2025-02-11T09:36:36","date_gmt":"2025-02-11T00:36:36","guid":{"rendered":"https:\/\/itexplore.org\/jp\/?p=158"},"modified":"2025-02-11T09:36:38","modified_gmt":"2025-02-11T00:36:38","slug":"substring-from-end-javascript","status":"publish","type":"post","link":"https:\/\/itexplore.org\/jp\/tips\/substring-from-end-javascript\/","title":{"rendered":"JavaScript\u3067\u5f8c\u308d\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3059\u308b"},"content":{"rendered":"<p>JavaScript\u3067\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\u3092\u53d6\u308a\u51fa\u3059\u306b\u306f\u3001<strong><span data-color=\"#fffd6b\" style=\"background: linear-gradient(transparent 60%,rgba(255, 253, 107, 0.7) 0);\" class=\"vk_highlighter\">\u6587\u5b57\u5217\u306e\u9577\u3055\u304b\u3089\u53d6\u5f97\u3057\u305f\u3044\u90e8\u5206\u6587\u5b57\u5217\u306e\u9577\u3055\u3092\u5f15\u3044\u305f\u4f4d\u7f6e\u304b\u3089\u5f8c\u306e\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3059\u308b<\/span><\/strong>\u6b63\u898f\u8868\u73fe\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p><p>JavaScript\u306esubstring\u30e1\u30bd\u30c3\u30c9\u3067\u306f\u3001\u7d75\u6587\u5b57\u3084\u300c\ud842\udfb7\u300d\u306a\u3069\u306e\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u3092\u4f7f\u3063\u305f2\u30b3\u30fc\u30c9\u30e6\u30cb\u30c3\u30c8\u3067\u8868\u73fe\u3055\u308c\u308b\u6587\u5b57\u304c\u6b63\u3057\u304f\u51e6\u7406\u3067\u304d\u306a\u3044\u305f\u3081\u3001\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p><h2 class=\"wp-block-heading\">\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9<\/h2><div class=\"input-field-container source-code-container\"><pre class=\"wp-block-code\"><code>\/**\n * \u6307\u5b9a\u3055\u308c\u305f\u6587\u5b57\u5217\u306e\u5f8c\u308d\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3057\u307e\u3059\n *\n * @param {string} str \u6587\u5b57\u5217\n * @param {number} len \u90e8\u5206\u6587\u5b57\u5217\u306e\u9577\u3055\uff08\u6841\u6570\uff09\n * @returns {string} \u90e8\u5206\u6587\u5b57\u5217\n *\/\nconst substringFromEnd = (str, len) => {\n\tif (len < 0) {\n\t\tlen = 0;\n\t}\n\n\tconst strLen = Array.from(str).length;\n\n\tif (strLen < len) {\n\t\treturn str;\n\t}\n\n\tconst reg = new RegExp(`^.{${strLen - len}}(.{0,${len}})`, 'u');\n\treturn str.match(reg)?.[1];\n};\n<\/code><\/pre><a id=\"copy-source-code-JavaScript-substringFromEnd\" class=\"action-button enable copy-source-code\" title=\"\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3092\u30b3\u30d4\u30fc\u3057\u307e\u3059\u3002\"><i class=\"fa-regular fa-copy\"><\/i><\/a><\/div><p class=\"border-spacer\"><\/p><h2 class=\"wp-block-heading\">\u691c\u8a3c<\/h2><p>\u6587\u5b57\u5217\u3068\u90e8\u5206\u6587\u5b57\u5217\u306e\u9577\u3055\uff08\u6841\u6570\uff09\u3092\u6307\u5b9a\u3057\u3066\u95a2\u6570\u3092\u5b9f\u884c\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p><div class=\"verify-container source-code-container\"><div class=\"wp-block-buttons is-layout-flex wp-block-buttons-between\"><div><span style=\"font-weight:bold\">\u5f15\u6570\u306e\u5165\u529b<\/span><\/div><\/div><p class=\"border-spacer\" style=\"margin-top: -10px;\"><\/p><div class=\"flex-vertical-align-center-container\"><span class=\"inline-block\">substringFromEnd(<\/span><div class=\"flex-vertical-align-center-container\">\"&nbsp;<div class=\"input-field-container inline-block\" style=\"width: 15rem;\"><input type=\"text\" id=\"input-str\" value=\"\" maxlength=\"64\" placeholder=\"\u6587\u5b57\u5217\u3092\u5165\u529b\"><a id=\"clear-str\" class=\"action-button risky-link no-disable-control\" title=\"\u6587\u5b57\u5217\u3092\u524a\u9664\u3057\u307e\u3059\u3002\"><i class=\"fa-regular fa-circle-xmark\"><\/i><\/a><\/div>&nbsp;<\/div><span class=\"inline-block\">,<\/span><div class=\"flex-vertical-align-center-container\">\"&nbsp;<div class=\"input-field-container inline-block\" style=\"width: 10rem;\"><input type=\"text\" id=\"input-substring-length\" value=\"\" maxlength=\"2\" placeholder=\"\u9577\u3055\u3092\u5165\u529b\"><a id=\"clear-substring-length\" class=\"action-button risky-link no-disable-control\" title=\"\u90e8\u5206\u6587\u5b57\u5217\u306e\u9577\u3055\u3092\u524a\u9664\u3057\u307e\u3059\u3002\"><i class=\"fa-regular fa-circle-xmark\"><\/i><\/a><\/div>&nbsp;);<\/div><\/div><p class=\"border-spacer\" style=\"margin-top: -10px;\"><\/p><div class=\"wp-block-buttons is-layout-flex wp-block-buttons-between\"><div class=\"wp-block-button tooltip-container\"><a id=\"clear-information\" class=\"wp-block-button__link wp-element-button risky-action-button\" title=\"\u5f15\u6570\u5165\u529b\u6b04\u3068\u691c\u8a3c\u7d50\u679c\u3092\u30af\u30ea\u30a2\u3057\u307e\u3059\u3002\"><i class=\"fa-solid fa-eraser\"><\/i>\u30af\u30ea\u30a2<\/a><\/div><div class=\"wp-block-button\"><a id=\"execute-function\" class=\"wp-block-button__link wp-element-button\" title=\"\u6587\u5b57\u5217\u306e\u5f8c\u308d\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3057\u307e\u3059\u3002\"><i class=\"fa-solid fa-bolt\"><\/i>\u5b9f\u884c<\/a><\/div><\/div><\/div><p class=\"border-spacer\"><\/p><h3 class=\"wp-block-heading\">\u691c\u8a3c\u7d50\u679c<\/h3><div id=\"execute-function-result\" class=\"verify-container\"><\/div><p class=\"border-spacer\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>JavaScript\u3067\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\u3092\u53d6\u308a\u51fa\u3059\u306b\u306f\u3001\u6587\u5b57\u5217\u306e\u9577\u3055\u304b\u3089\u53d6\u5f97\u3057\u305f\u3044\u90e8\u5206\u6587\u5b57\u5217\u306e\u9577\u3055\u3092\u5f15\u3044\u305f\u4f4d\u7f6e\u304b\u3089\u5f8c\u306e\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3059\u308b\u6b63\u898f\u8868\u73fe\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n","protected":false},"author":1,"featured_media":160,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"vkexunit_cta_each_option":"","footnotes":""},"categories":[4],"tags":[11],"class_list":["post-158","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tips","tag-javascript"],"_links":{"self":[{"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/posts\/158","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/comments?post=158"}],"version-history":[{"count":2,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/posts\/158\/revisions"}],"predecessor-version":[{"id":161,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/posts\/158\/revisions\/161"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/media\/160"}],"wp:attachment":[{"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/media?parent=158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/categories?post=158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itexplore.org\/jp\/wp-json\/wp\/v2\/tags?post=158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}