<\/div>\n

Programlamada manuel olarak “null” de\u011ferini kulland\u0131\u011f\u0131m\u0131z alanlardan ziyade, dinamik olarak de\u011fi\u015fkenlik g\u00f6sterebilen ve ne zaman nerede kar\u015f\u0131m\u0131za \u00e7\u0131kabilece\u011fini bilemeyece\u011fimiz durumlarda “null” de\u011feri olduk\u00e7a problem yaratabiliyor. Genellikle veritaban\u0131ndan elde etti\u011fimiz veriler i\u00e7erisinde i\u015flemlerimizi ger\u00e7ekle\u015ftirirken “null” de\u011ferinin bizleri peri\u015fan etti\u011fi durumlar\u0131 \u00e7ok g\u00f6rm\u00fc\u015f\u00fczd\u00fcr. Haliyle C# ve di\u011fer programlama dilleri “null” de\u011ferine \u00f6zel kontrol s\u0131n\u0131flar\u0131 veyahut mekanizmalar\u0131 olu\u015fturmaktad\u0131rlar. Bu yaz\u0131m\u0131zda sizlere “null” de\u011ferini kontrol ama\u00e7l\u0131 in\u015fa edilmi\u015f Generic Nullable<\/em><\/strong> s\u0131n\u0131f\u0131 ile ??<\/em><\/strong> operat\u00f6r\u00fcn\u00fc tan\u0131taca\u011f\u0131m.<\/p>\n

Nullable S\u0131n\u0131f\u0131<\/span><\/h2>\n
Generic olarak tan\u0131mlanm\u0131\u015f bir s\u0131n\u0131ft\u0131r. Elde edilen verinin “null” olma durumuna g\u00f6re kontrol yapmam\u0131z\u0131 sa\u011flar.<\/p>\n
\r\n static void Islem(Nullable<int> Sayi) {\r\n if (!Sayi.HasValue)\r\n {\r\n Console.WriteLine("Say\u0131 girilmemi\u015ftir.");\r\n }\r\n else\r\n {\r\n Console.WriteLine("Girilen say\u0131 : " + Sayi.Value);\r\n }\r\n }\r\n<\/pre>\n
HasValue<\/strong> <\/em>\u00f6zelli\u011fi sayesinde de\u011fer var m\u0131? yok mu? kontrol edilmektedir.
\nValue<\/strong> <\/em>\u00f6zelli\u011fi sayesinde de, e\u011fer de\u011fer varsa o de\u011feri elde edebilmekteyiz.<\/p>\n
?? Operat\u00f6r\u00fc<\/span><\/h2>\n
Bu operat\u00f6r ile k\u0131sa ve net bir gramerle null de\u011ferleri kontrol edebiliyor ve m\u00fcdahale edebiliyoruz. \u015eimdi a\u015fa\u011f\u0131daki kod blo\u011funu inceleyiniz.<\/p>\n
\r\n static void Islem(int? Sayi)\r\n {\r\n Sayi = Sayi ?? -1;\r\n Console.WriteLine(Sayi.Value);\r\n }\r\n<\/pre>\n
G\u00f6rd\u00fc\u011f\u00fcn\u00fcz gibi Sayi parametresine null de\u011fer girilirse ?? operat\u00f6r\u00fc ile kontrol edilmektedir. Okunu\u015fu \u015f\u00f6yledir. E\u011fer Say\u0131 de\u011feri null ise -1 de\u011ferini ata. \u0130\u015flemimiz bu kadar kolay…<\/p>\n
Tabi genellikle Asp.NET MVC mimarisinde kulland\u0131\u011f\u0131m\u0131z bu operat\u00f6r\u00fc birde o mimaride inceleyelim.<\/p>\n
\r\n public ContentResult Topla(int? Sayi1, int? Sayi2)\r\n {\r\n Sayi1 = Sayi1 ?? 0;\r\n Sayi2 = Sayi2 ?? 0;\r\n return Content((Sayi1 + Sayi2).ToString());\r\n }\r\n<\/pre>\n
Hepinize kolay gelsin…
\n\u0130yi \u00e7al\u0131\u015fmalar dilerim…<\/p>\n","protected":false},"excerpt":{"rendered":"
Programlamada manuel olarak “null” de\u011ferini kulland\u0131\u011f\u0131m\u0131z alanlardan ziyade, dinamik olarak de\u011fi\u015fkenlik g\u00f6sterebilen ve ne zaman nerede kar\u015f\u0131m\u0131za \u00e7\u0131kabilece\u011fini bilemeyece\u011fimiz durumlarda “null” de\u011feri olduk\u00e7a problem yaratabiliyor. Genellikle veritaban\u0131ndan elde etti\u011fimiz veriler i\u00e7erisinde i\u015flemlerimizi ger\u00e7ekle\u015ftirirken “null”...<\/p>\n","protected":false},"author":1,"featured_media":3014,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,600,12,720,345],"tags":[898,897,27,895,896,894,335],"class_list":["post-3528","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-asp-net","category-asp-net-mvc-5","category-c-sharp-c","category-c-6-0","category-mvc-4-0","tag-898","tag-operatoru","tag-c","tag-hasvalue","tag-null","tag-nullable","tag-value"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/3528","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/comments?post=3528"}],"version-history":[{"count":0,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/3528\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media\/3014"}],"wp:attachment":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media?parent=3528"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/categories?post=3528"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/tags?post=3528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}