{"id":2997,"date":"2018-05-24T20:18:55","date_gmt":"2018-05-24T11:18:55","guid":{"rendered":"http:\/\/taitan916.info\/blog\/?p=2997"},"modified":"2024-03-13T23:07:35","modified_gmt":"2024-03-13T14:07:35","slug":"post-2997","status":"publish","type":"post","link":"https:\/\/taitan916.info\/blog\/archives\/2997","title":{"rendered":"JavaScript\u3067\u5c0f\u6570\u306e\u8a08\u7b97\u3092\u3059\u308b\u969b\u306b\u305a\u308c(\u8aa4\u5dee)\u3092\u7121\u304f\u3059\u65b9\u6cd5(decimal.js)"},"content":{"rendered":"

JavaScript\u3067\u5c0f\u6570\u306e\u8a08\u7b97\u3092\u3059\u308b\u3068\u5024\u304c\u305a\u308c\u308b(\u8aa4\u5dee\u304c\u767a\u751f\u3059\u308b)\u3053\u3068\u304c\u3042\u3063\u305f\u3002\u8abf\u3079\u3066\u307f\u308b\u3068JavaScript\u306fIEEE754<\/a>\u3068\u304b\u3044\u3046\u898f\u683c\u306b\u305d\u3063\u3066\u5b9f\u88c5\u3055\u308c\u3066\u304a\u308a\u3001\u305d\u306e\u305b\u3044\u3067\u8aa4\u5dee\u304c\u751f\u307e\u308c\u308b\u3089\u3057\u3044\u3002\u81ea\u4f5c\u95a2\u6570\u3068\u304b\u3067\u4f55\u3068\u304b\u3059\u308b\u65b9\u6cd5\u3068\u30e9\u30a4\u30d6\u30e9\u30ea\u3067\u5bfe\u5fdc\u3059\u308b\u65b9\u6cd5\u304c\u3042\u308a\u3001\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u65b9\u304c\u697d\u305d\u3046\u3060\u3063\u305f\u306e\u3067\u4f7f\u7528\u65b9\u6cd5\u306e\u30e1\u30e2\u3002<\/p>\n

 <\/p>\n

\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u7528\u610f<\/h2>\n

\u81ea\u30b5\u30fc\u30d0\u306b\u30a2\u30c3\u30d7\u30ed\u30fc\u30c9\u3059\u308b\u5834\u5408<\/h3>\n

\u4ee5\u4e0b\u304b\u3089decimal.js\u3092\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9\u3057\u3001\u9069\u5f53\u306a\u30c7\u30a3\u30ec\u30af\u30c8\u30ea\u306b\u30a2\u30c3\u30d7\u30ed\u30fc\u30c9\u3059\u308b\u3002<\/p>\n

https:\/\/github.com\/MikeMcl\/decimal.js\/<\/a><\/p>\n

CDN\u3067\u5229\u7528\u3059\u308b\u5834\u5408<\/h3>\n

\u4ee5\u4e0b\u3092\u8a18\u8ff0\u3059\u308b\u3002<\/p>\n

<script src=\"https:\/\/cdnjs.cloudflare.com\/ajax\/libs\/decimal.js\/9.0.0\/decimal.min.js\"><\/script><\/pre>\n
\u30d0\u30fc\u30b8\u30e7\u30f3\u3092\u5909\u66f4\u3057\u305f\u3044\u5834\u5408\u306f\u4ee5\u4e0b\u304b\u3089\u63a2\u3059\u3002<\/p>\n
https:\/\/cdnjs.com\/libraries\/decimal.js\/9.0.0<\/a><\/p>\n
\u30ea\u30d5\u30a1\u30ec\u30f3\u30b9<\/h3>\n
https:\/\/mikemcl.github.io\/decimal.js\/<\/a><\/p>\n
 <\/p>\n
\u4f7f\u3044\u65b9<\/h2>\n
let dec = new Decimal(0.001);\r\n\r\n\/\/\u8db3\u3057\u7b97\r\ndec = dec.plus(0.001);\r\n\r\n\/\/\u5f15\u304d\u7b97\r\ndec = dec.minus(0.001);\r\n\r\n\/\/\u639b\u3051\u7b97\r\ndec = dec.times(0.001);\r\n\r\n\/\/\u5272\u308a\u7b97\r\ndec = dec.div(0.001);\r\n\r\n\/\/\u6570\u5024\u5316\r\nconst num = dec.toNumber();\r\n\r\n\/\/\u30e1\u30bd\u30c3\u30c9\u30c1\u30a7\u30fc\u30f3\u307f\u305f\u3044\u306b\u3082\u4f7f\u3048\u308b\r\nconsole.log(dec.times(0.01).toNumber());<\/pre>\n
toNumber()\u3067\u6570\u5024\u5316\u3057\u306a\u3044\u3068\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u8fd4\u3063\u3066\u304f\u308b<\/strong>\u306e\u3067\u6ce8\u610f\u3059\u308b\u3002<\/p>\n
 <\/p>\n
\u30bd\u30fc\u30b9<\/h2>\n
\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9<\/h3>\n
<script>\r\nconst a = 0.01;\r\nconst b = 0.0001;\r\nconsole.log(a * b); \/\/0.0000010000000000000002\u304c\u8868\u793a\u3055\u308c\u308b\r\n\r\nconst dec = new Decimal(a);\r\nconsole.log(dec.times(b).toNumber()); \/\/0.000001\u304c\u8868\u793a\u3055\u308c\u308b\r\n<\/script><\/pre>\n
\u6d88\u8cbb\u7a0e\u306e\u8a08\u7b97\u30b5\u30f3\u30d7\u30eb<\/h3>\n
<script>\r\nconst tax = 1.1;\r\nconst price = 1650;\r\nconst total_price = tax * price;\r\nconsole.log(total_price); \/\/1815.0000000000002\u304c\u8868\u793a\u3055\u308c\u308b\r\n\r\nconst tax = new Decimal(1.1);\r\nconst price = 1650;\r\nconst total_price = tax.times(price).toNumber();\r\nconsole.log(total_price); \/\/1815\u304c\u8868\u793a\u3055\u308c\u308b\r\n<\/script><\/pre>\n
 <\/p>\n
\u53c2\u8003\u30b5\u30a4\u30c8<\/h2>\n
http:\/\/laxmi759.blog.fc2.com\/blog-entry-92.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
JavaScript\u3067\u5c0f\u6570\u306e\u8a08\u7b97\u3092\u3059\u308b\u3068\u5024\u304c\u305a\u308c\u308b(\u8aa4\u5dee\u304c\u767a\u751f\u3059\u308b)\u3053\u3068\u304c\u3042\u3063\u305f ... <\/p>\n","protected":false},"author":1,"featured_media":1067,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4],"tags":[100],"class_list":["post-2997","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript","tag-library"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/posts\/2997","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/comments?post=2997"}],"version-history":[{"count":10,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/posts\/2997\/revisions"}],"predecessor-version":[{"id":4583,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/posts\/2997\/revisions\/4583"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/media\/1067"}],"wp:attachment":[{"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/media?parent=2997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/categories?post=2997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/taitan916.info\/blog\/wp-json\/wp\/v2\/tags?post=2997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}