{"id":1868,"date":"2020-05-26T14:25:35","date_gmt":"2020-05-26T14:25:35","guid":{"rendered":"https:\/\/yazilimperver.com\/?p=1868"},"modified":"2020-05-26T14:25:35","modified_gmt":"2020-05-26T14:25:35","slug":"haftalik-c-28-onaltili-kayan-noktali-sayi-sabitleri-floating-point-literals","status":"publish","type":"post","link":"https:\/\/yazilimperver.com\/index.php\/2020\/05\/26\/haftalik-c-28-onaltili-kayan-noktali-sayi-sabitleri-floating-point-literals\/","title":{"rendered":"[:tr]Haftal\u0131k C++ 28 \u2013 Onalt\u0131l\u0131 kayan noktal\u0131 say\u0131 sabitleri (Floating point literals)[:]"},"content":{"rendered":"

[:tr]Evet arkada\u015flar, modern C++ ile gelen kabiliyetlere g\u00f6z atmaya devam ediyoruz. Bu yaz\u0131mda da, k\u0131saca C++ 17 ile gelen bir kabiliyetten bahsedece\u011fim:Onalt\u0131l\u0131 kayan noktal\u0131 (floating) say\u0131 sabitleri<\/em>.<\/p>\n

Normalde tam say\u0131lar i\u00e7in C ve C++ da onalt\u0131l\u0131 d\u00fczende sabitler tan\u0131mlanabilse de, kayan noktal\u0131 say\u0131lar i\u00e7in b\u00f6yle bir kabliyet yoktu, c++ 17 ile birlikte art\u0131k var.
\nHemen bu say\u0131lar\u0131n nas\u0131l tan\u0131mlanabilece\u011fine bakal\u0131m:<\/p>\n

“0x<Onalt\u0131l\u0131k Tamsay\u0131 K\u0131sm\u0131>.<Onalt\u0131l\u0131k kesirli k\u0131sm\u0131>p<\u0130kinin ka\u00e7\u0131nc\u0131 kuvveti oldu\u011fu>”<\/strong><\/span><\/p>\n

\u015feklinde tan\u0131mlanabilmektedir. Exponent p k\u0131sm\u0131 bu sabitler i\u00e7in her zaman eklenmelidir. Noktan \u00f6nce 16 ve katlar\u0131 sonras\u0131nda ise 1\/16 ve katlar\u0131 olarak say\u0131 hesaplan\u0131p, en son p ye g\u00f6re, b\u00fct\u00fcn say\u0131 \u00e7arp\u0131larak sabit elde edilmekte. Hemen \u00f6rnekler \u00fczerinden gidelim:<\/p>\n

#include <iostream>\r\n\r\nint main()\r\n{\r\n      std::cout << \"\\\"0x0p0\\\"    : \" << 0x0p0     << \"\\n\"; \/\/ ( 0.0 + 0.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x0.p0\\\"   : \" << 0x0.p0    << \"\\n\"; \/\/ ( 0.0 + 0.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x.1p0\\\"   : \" << 0x.1p0    << \"\\n\"; \/\/ ( 0.0 + 1.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x0.1p0\\\"  : \" << 0x0.1p0   << \"\\n\"; \/\/ ( 0.0 + 1.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x1.1p0\\\"  : \" << 0x1.1p0   << \"\\n\"; \/\/ ( 1.0 + 1.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x1.2p0\\\"  : \" << 0x1.2p0   << \"\\n\"; \/\/ ( 1.0 + 2.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x2.2p0\\\"  : \" << 0x2.2p0   << \"\\n\"; \/\/ ( 2.0 + 2.0\/16 )*(2 uzeri 0)\r\n      std::cout << \"\\\"0x2.2p1\\\"  : \" << 0x2.2p1   << \"\\n\"; \/\/ ( 2.0 + 2.0\/16 )*(2 uzeri 1)\r\n      std::cout << \"\\\"0x2.2p2\\\"  : \" << 0x2.2p2   << \"\\n\"; \/\/ ( 2.0 + 2.0\/16 )*(2 uzeri 2)\r\n      std::cout << \"\\\"0x10.01p0\\\": \" << 0x10.01p0 << \"\\n\"; \/\/ (16.0 + 1.0\/(16 uzeri 2))*(2 uzeri 0)\r\n      std::cout << \"\\\"0x10.01p1\\\": \" << 0x10.01p1 << \"\\n\"; \/\/ (16.0 + 1.0\/(16 uzeri 2))*(2 uzeri 1)\r\n      std::cout << \"\\\"0x10.01p-1\\\": \" << 0x10.01p-1 << \"\\n\"; \/\/ (16.0 + 1.0\/(16 uzeri 2))*(2 uzeri -1). Buna dikkat carptigimiz sayi 0.5 oluyor. yani 1\/2\r\n      std::cout << \"\\\"0x0.001p0\\\": \" << 0x0.001p0 << \"\\n\"; \/\/ (16.0 + 1.0\/(16 uzeri 3))*(2 uzeri 0)\r\n      \r\n      return 0;\r\n}<\/pre>\n
Yukar\u0131daki \u00f6rnek kodun \u00e7\u0131kt\u0131s\u0131 da a\u015fa\u011f\u0131daki gibi olacakt\u0131r:<\/p>\n
\"0x0p0\"    : 0\r\n\"0x0.p0\"   : 0\r\n\"0x.1p0\"   : 0.0625\r\n\"0x0.1p0\"  : 0.0625\r\n\"0x1.1p0\"  : 1.0625\r\n\"0x1.2p0\"  : 1.125\r\n\"0x2.2p0\"  : 2.125\r\n\"0x2.2p1\"  : 4.25\r\n\"0x2.2p2\"  : 8.5\r\n\"0x10.01p0\": 16.0039\r\n\"0x10.01p1\": 32.0078\r\n\"0x10.01p-1\": 8.00195\r\n\"0x0.001p0\": 0.000244141<\/pre>\n
Kaynaklar<\/span><\/strong><\/h2>\n