{"title":"JavaScript \u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u5909\u63db\uff1atoUpperCase \u3068 toLowerCase","version":"1.0","categories":["JavaScript","TypeScript"],"author_url":"https://blog.hatena.ne.jp/plarail_hangout/","description":"JavaScript \u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u5909\u63db\uff1atoUpperCase \u3068 toLowerCase JavaScript \u3067\u6587\u5b57\u5217\u3092\u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u306b\u306f toUpperCase() \u3068 toLowerCase() \u3092\u4f7f\u3044\u307e\u3059\u3002\u3069\u3061\u3089\u3082\u5f15\u6570\u306a\u3057\u3067\u547c\u3073\u51fa\u3059\u3060\u3051\u3067\u52d5\u4f5c\u3057\u307e\u3059\u3002 toUpperCase()\uff1a\u3059\u3079\u3066\u5927\u6587\u5b57\u306b\u5909\u63db const str = 'Hello, World!' console.log(str.toUpperCase()) // 'HELLO, WORLD!' toLowerCase()\uff1a\u3059\u3079\u3066\u5c0f\u6587\u5b57\u306b\u5909\u63db const str = 'Hello, World!' console.l\u2026","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ftech.fun-toy-life.com%2Fentry%2F2026%2F07%2F05%2F095152\" title=\"JavaScript \u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u5909\u63db\uff1atoUpperCase \u3068 toLowerCase - Engineering Tech Dojo\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","type":"rich","height":"190","author_name":"plarail_hangout","published":"2026-07-05 09:51:52","provider_name":"Hatena Blog","provider_url":"https://hatena.blog","width":"100%","url":"https://tech.fun-toy-life.com/entry/2026/07/05/095152","blog_url":"https://tech.fun-toy-life.com/","image_url":null,"blog_title":"Engineering Tech Dojo"}