{"id":776,"date":"2012-11-28T18:01:47","date_gmt":"2012-11-28T09:01:47","guid":{"rendered":"http:\/\/www.techscore.com\/blog\/?p=776"},"modified":"2018-11-14T16:33:59","modified_gmt":"2018-11-14T07:33:59","slug":"%e6%95%b0%e5%80%a4-%e2%87%94-%e6%96%87%e5%ad%97%e5%88%97%e5%a4%89%e6%8f%9b-java%e7%b7%a8","status":"publish","type":"post","link":"https:\/\/www.techscore.com\/blog\/2012\/11\/28\/%e6%95%b0%e5%80%a4-%e2%87%94-%e6%96%87%e5%ad%97%e5%88%97%e5%a4%89%e6%8f%9b-java%e7%b7%a8\/","title":{"rendered":"\u3042\u3048\u3066\u8a00\u3046\u307b\u3069\u3067\u306f\u306a\u3044 \u6570\u5024 \u21d4 \u6587\u5b57\u5217\u5909\u63db Java\u7de8"},"content":{"rendered":"<p>\u3053\u3093\u306b\u3061\u306f\u5143Java\u30d7\u30ed\u30b0\u30e9\u30de\u306e\u6751\u4e0a\u3067\u3059\u3002<\/p>\n<p>\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3057\u3066\u3044\u308b\u6642\u306b \u6587\u5b57\u5217 \u21d4 \u6570\u5024 \u306e\u5909\u63db\u3063\u3066\u3088\u304f\u3084\u308a\u307e\u3059\u3088\u306d\uff1f<br \/>\nJava\u3067\u306e\u738b\u9053\u306f<\/p>\n<h2>\u6570\u5024 \u21d2 \u6587\u5b57\u5217<\/h2>\n<pre class=\"lang:java decode:true \">\r\nString s = String.valueOf(i);\r\n<\/pre>\n<h2>\u6587\u5b57\u5217 \u21d2 \u6570\u5024<\/h2>\n<pre class=\"lang:java decode:true \">\r\nint i = Integer.parseInt(s);\r\n<\/pre>\n<p>Java\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u898f\u7d04\u306a\u3069\u3067\u3082\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\n\u3067\u3082\u3053\u3093\u306a\u65b9\u6cd5\u3067\u3082\u5909\u63db\u306f\u3067\u304d\u307e\u3059\u3002<\/p>\n<h2>\u6570\u5024 \u21d2 \u6587\u5b57\u5217<\/h2>\n<pre class=\"lang:java decode:true \">\r\nString s = \"\" + i; \r\nString s = new Integer(i).toString();\r\nString s = Integer.toString(i);\r\n<\/pre>\n<h2>\u6587\u5b57\u5217 \u21d2 \u6570\u5024<\/h2>\n<pre class=\"lang:java decode:true \">\r\nint i = new Integer(s).intValue();\r\nint i = Integer.valueOf(s).intValue();\r\n<\/pre>\n<p>\u3067\u3082\u3042\u307e\u308a\u63a8\u5968\u306f\u3055\u308c\u3066\u3044\u307e\u305b\u3093\u3002<br \/>\n\u53ef\u8aad\u6027\u3067\u3042\u3063\u305f\u308a\u3001\u52b9\u7387\u304c\u60aa\u304b\u3063\u305f\u308a\u3068\u3044\u3046\u7406\u7531\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u672c\u5f53\u306b\u305d\u3046\u306a\u306e\u304b\uff1f<br \/>\n\u306a\u306e\u3067\u3001\u52b9\u7387\u304c\u672c\u5f53\u306b\u60aa\u3044\u306e\u304b\u8a08\u6e2c\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\u30b5\u30f3\u30d7\u30eb\u3068\u3057\u3066\u3053\u3093\u306a\u30b3\u30fc\u30c9\u3067\u3084\u3063\u3066\u307f\u307e\u3059\u3002<\/p>\n<pre class=\"lang:java decode:true \">\r\nfor (int i = 0; i < 10000000; i++) {\r\n\tString s = String.valueOf(i); \/\/ \u3053\u3053\u3092\u9806\u756a\u306b\u5909\u3048\u3066\u898b\u307e\u3059\u3002\r\n}\r\n<\/pre>\n<p>10\u56de\u884c\u3063\u305f\u5e73\u5747\u306e\u6642\u9593\u3092\u6e2c\u3063\u3066\u307f\u308b\u3068\u3053\u3093\u306a\u611f\u3058\u3067\u3057\u305f\u3002<br \/>\n\u5358\u4f4d\u306f\u30df\u30ea\u79d2\u3067\u3059\u3002<\/p>\n<table>\n<tr>\n<th>\u6570\u5024 \u21d2 \u6587\u5b57\u5217<\/th>\n<th>Java5<\/th>\n<th>Java6<\/th>\n<th>Java7<\/th>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>String s = String.valueOf(i);<\/td>\n<td>649<\/td>\n<td>442<\/td>\n<td>342<\/td>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>String s = \"\" + i;<\/td>\n<td>995<\/td>\n<td>736<\/td>\n<td>363<\/td>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>String s = new Integer(i).toString();<\/td>\n<td>709<\/td>\n<td>461<\/td>\n<td>342<\/td>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>String s = Integer.toString(i);<\/td>\n<td>623<\/td>\n<td>419<\/td>\n<td>342<\/td>\n<\/tr>\n<th>\u6587\u5b57\u5217 \u21d2 \u6570\u5024<\/th>\n<th>Java5<\/th>\n<th>Java6<\/th>\n<th>Java7<\/th>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>int i = Integer.parseInt(s);<\/td>\n<td>678<\/td>\n<td>459<\/td>\n<td>241<\/td>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>int i = new Integer(s).intValue();<\/td>\n<td>753<\/td>\n<td>492<\/td>\n<td>240<\/td>\n<\/tr>\n<tr style=\"background: none repeat scroll 0 0 #E5E4E8\">\n<td>int i = Integer.valueOf(s).intValue();<\/td>\n<td>768<\/td>\n<td>513<\/td>\n<td>275<\/td>\n<\/tr>\n<\/table>\n<p>Java\u306e\u9032\u5316\u306f\u3059\u3054\u3044\u3068\u3044\u3046\u306e\u3068Java7\u3067\u306f\u307b\u3068\u3093\u3069\u5dee\u304c\u306a\u3044\u3068\u3044\u3046\u4e8b\u304c\u308f\u304b\u308a\u307e\u3057\u305f\u306d(\u7b11)<br \/>\n\u3042\u3068\u3001\u4e88\u60f3\u5916\u3060\u3063\u305f\u306e\u306f\u300cString s = Integer.toString(i);\u300d\u304c\u4e00\u756a\u901f\u3044\u3093\u3067\u3059\u306d\u3002<br \/>\n\u3067\u3082\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3068\u304d\u306f\u52b9\u7387\u306e\u826f\u3055\u3060\u3051\u3067\u306f\u306a\u304f\u3066\u3001\u53ef\u8aad\u6027\u3082\u91cd\u8981\u306a\u306e\u3067\u305d\u3053\u3089\u8fba\u3082\u8003\u3048\u3066\u898f\u7d04\u306f\u6c7a\u3081\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u306d\u3002<\/p>\n<p>\u3061\u306a\u307f\u306b\u5909\u63db\u3059\u308b\u5909\u6570\u304c\u5b9a\u6570\u3060\u3063\u305f\u5834\u5408<\/p>\n<pre class=\"lang:java decode:true \">\r\nfor (int i = 0; i < 10000000; i++) {\r\n\tString s = \"\" + 1000; \r\n}\r\n<\/pre>\n<p>Java5\u306712\u30df\u30ea\u79d2\u3067\u30c0\u30f3\u30c8\u30c4\u3067\u3059\u3002<br \/>\nJava7\u3060\u3068\u30df\u30ea\u79d2\u306e\u7cbe\u5ea6\u3067\u306f0\u306b\u306a\u308a\u307e\u3059\u3002<strong>\u7206\u901f<\/strong>\u3067\u3059\u3002<\/p>\n<p>\u305f\u3076\u3093\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u6700\u9069\u5316\u3055\u308c\u3066\u308b\u3068\u601d\u3044\u307e\u3059\u3002<br \/>\n\u4ed6\u306e\u30b3\u30fc\u30c9\u306f\u5b9a\u6570\u306e\u6642\u3067\u3082\u5909\u308f\u308a\u307e\u305b\u3093\u3067\u3057\u305f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u3053\u3093\u306b\u3061\u306f\u5143Java\u30d7\u30ed\u30b0\u30e9\u30de\u306e\u6751\u4e0a\u3067\u3059\u3002<br \/><a href=\"https:\/\/www.techscore.com\/blog\/2012\/11\/28\/%e6%95%b0%e5%80%a4-%e2%87%94-%e6%96%87%e5%ad%97%e5%88%97%e5%a4%89%e6%8f%9b-java%e7%b7%a8\/\">\u7d9a\u304d\u3092\u8aad\u3080...<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[18],"tags":[57,28],"_links":{"self":[{"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/posts\/776"}],"collection":[{"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/comments?post=776"}],"version-history":[{"count":2,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/posts\/776\/revisions"}],"predecessor-version":[{"id":18014,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/posts\/776\/revisions\/18014"}],"wp:attachment":[{"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/media?parent=776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/categories?post=776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techscore.com\/blog\/wp-json\/wp\/v2\/tags?post=776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}