De\u011fi\u015fken kavram\u0131, t\u00fcm programlama dillerinde hayat\u0131m\u0131za girmi\u015f olan bir kavramd\u0131r. Dart programlama dilinde kendinize \u00f6zel t\u00fcrde de\u011fi\u015fken olu\u015fturabilir ya da sistemdeki dahili de\u011fi\u015fkenleri (Built-in Types) kullanabilirsiniz. Dart dilinde tan\u0131mlanm\u0131\u015f olan dahili de\u011fi\u015fkenler a\u015fa\u011f\u0131daki gibidir.<\/p>\n\n\n\n
Built-in Types:<\/strong><\/span><\/p>\n\n\n\n Dart dilinde say\u0131sal ifadeler “num”<\/strong> s\u0131n\u0131f\u0131ndan t\u00fcretilmi\u015ftir. Bu s\u0131n\u0131f dart:math<\/strong> k\u00fct\u00fcphanesi alt\u0131nda bulunmaktad\u0131r. E\u011fer bu t\u00fcrde de\u011fi\u015fkenler tan\u0131mlayam\u0131yor iseniz, bu k\u00fct\u00fcphaneyi ilgili s\u0131n\u0131f\u0131n\u0131za import etmelisiniz.<\/p>\n\n\n\n int:<\/strong><\/em><\/span> Tam say\u0131 de\u011ferlerinin tutuldu\u011fu de\u011fi\u015fken t\u00fcr\u00fcd\u00fcr. Alt ve \u00fcst de\u011fer limitleri platforma ba\u011f\u0131ml\u0131 olarak de\u011fi\u015febilir.<\/p>\n\n\n\n double<\/span>:<\/strong><\/em> Virg\u00fcll\u00fc ifadelerin tutuldu\u011fu say\u0131 de\u011fi\u015fken format\u0131d\u0131r.<\/p>\n\n\n\n String<\/span><\/em>:<\/strong> Yaz\u0131 ifadelerinde bu de\u011fi\u015fken t\u00fcr\u00fc kullan\u0131lmaktad\u0131r. Tek t\u0131rnak(‘) veya \u00e7ift t\u0131rnaklar(“) aras\u0131na de\u011fi\u015fkeninizi tan\u0131mlayabilirsiniz. Burada dikkat etmeniz gereken nokta ba\u015flad\u0131\u011f\u0131n\u0131z ifade ile sonland\u0131rmal\u0131s\u0131n\u0131z. Yaz\u0131 i\u00e7erisinde ba\u015flad\u0131\u011f\u0131n\u0131z ifadeyi yeniden kullanmak i\u00e7in a\u015fa\u011f\u0131daki gibi tan\u0131mlamalar yapabilirsiniz. Yazi i\u00e7erisine ba\u015fka bir de\u011fi\u015fken g\u00f6ndermek istiyorsan\u0131z, de\u011fi\u015fken ad\u0131n\u0131n ba\u015f\u0131na “$” simgesi koymal\u0131s\u0131n\u0131z.(\u00d6rn: String variableString)<\/p>\n\n\n\n E\u011fer tan\u0131mlayaca\u011f\u0131n\u0131z yaz\u0131 t\u00fcr\u00fc birden fazla sat\u0131rdan olu\u015fuyor ise, tek t\u0131rnak veya \u00e7ift t\u0131rnak ifadesini 3 defa kullanmal\u0131s\u0131n\u0131z. Bu i\u015flemi \\n ile de yapabilirsiniz. Herhangi bir yerden kopyalad\u0131\u011f\u0131n\u0131z bir yaz\u0131 i\u00e7erisinde bir\u00e7ok \\n ifadesi var ve siz bunlar\u0131 kullanmak istemiyorsan\u0131z, yaz\u0131 ba\u015f\u0131na “r”<\/strong> karakterini koyarak alt sat\u0131ra ge\u00e7mesini engelleyebilirsiniz.<\/p>\n\n\n\n Yaz\u0131n\u0131z \u00e7ok uzun oldu\u011funda ekran geni\u015fli\u011fine s\u0131\u011fmayabilir, bu gibi durumlarda a\u015fa\u011f\u0131daki gibi bir kullan\u0131m ile metni alt sat\u0131rlara b\u00f6lebilirsiniz. Bu ifade alt alta yaz\u0131lan String ifadelerini birle\u015ftirir ve tek bir de\u011fi\u015fkende toplar.<\/p>\n\n\n\n bool<\/span>: <\/strong><\/em>Genelde karar ifadelerinde tutulmas\u0131nda kullan\u0131lan bir de\u011fi\u015fken t\u00fcr\u00fcd\u00fcr. Bu t\u00fcre sadece True ve False de\u011ferleri atanabilir. Yani sadece Do\u011fru ve Yanl\u0131\u015f se\u00e7eneklerinin oldu\u011fu bir oyun d\u00fc\u015f\u00fcn\u00fcn, bu oyunda kullan\u0131c\u0131n\u0131n se\u00e7imlerini de\u011fi\u015fkenlerde tutmak istedi\u011fimizde bu t\u00fcr\u00fc kullan\u0131l\u0131r\u0131z.<\/p>\n\n\n\n List<\/span>: <\/strong><\/em>S\u0131ral\u0131 nesne grubu olarak bilinir. Yani dizi \u015feklinde birden \u00e7ok ayn\u0131 veya farkl\u0131 t\u00fcre ait elemanlar\u0131 bu de\u011fi\u015fken i\u00e7erisinde tutar\u0131z. (\u00d6\u011frenci numaralar\u0131 listesi, alfabedeki harflerin listesi vb.) Birden fazla tan\u0131mlama yolu mevcuttur. Bunlardan en basit olan\u0131 k\u00f6\u015feli parantezler aras\u0131na liste elemanlar\u0131n\u0131 aralar\u0131na virg\u00fcl koyarak tan\u0131mlamakt\u0131r. A\u015fa\u011f\u0131da kullan\u0131m \u00f6rnekleri verilmi\u015ftir.<\/p>\n\n\n\n Map<\/strong><\/em><\/span>: <\/strong><\/em>Anahtar – de\u011fer ikilisine g\u00f6re verileri de\u011fi\u015fkende tutan bir t\u00fcrd\u00fcr. Anahtar ve de\u011feri herhangi bir obje t\u00fcr\u00fcnde olabilir. (int, String, bool, custom vb.) Anahtar tekil olmak zorundad\u0131r. De\u011fer tekil olmayabilir. Ayn\u0131 de\u011fer birden fazla anahtara atanabilir. \u00d6rnekler a\u015fa\u011f\u0131da verilmi\u015ftir.<\/p>\n\n\n\n De\u011fi\u015fken kavram\u0131, t\u00fcm programlama dillerinde hayat\u0131m\u0131za girmi\u015f olan bir kavramd\u0131r. Dart programlama dilinde kendinize \u00f6zel t\u00fcrde de\u011fi\u015fken olu\u015fturabilir ya da sistemdeki dahili de\u011fi\u015fkenleri (Built-in Types) kullanabilirsiniz. Dart dilinde tan\u0131mlanm\u0131\u015f olan dahili de\u011fi\u015fkenler a\u015fa\u011f\u0131daki gibidir. Built-in Types: Dart dilinde say\u0131sal ifadeler “num” s\u0131n\u0131f\u0131ndan t\u00fcretilmi\u015ftir. Bu s\u0131n\u0131f dart:math k\u00fct\u00fcphanesi alt\u0131nda bulunmaktad\u0131r. E\u011fer bu t\u00fcrde de\u011fi\u015fkenler tan\u0131mlayam\u0131yor iseniz, bu…<\/p>\n","protected":false},"author":1,"featured_media":2197,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[],"post_series":[],"class_list":["post-1939","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dart","entry","has-media"],"yoast_head":"\nint number = 5;\nint hex = 0xACACABCD;<\/code><\/pre>\n\n\n\ndouble number = 12.23;<\/code><\/pre>\n\n\n\nString singleQuote = 'Tek t\u0131rnak de\u011fi\u015fken tan\u0131mlama';\nString doubleQuote = \"\u00c7ift t\u0131rnak de\u011fi\u015fken tan\u0131mlama\";\nString singleQuote2 = 'Tek t\u0131rnak i\u00e7inde tekt\u0131rnak \\' kullan\u0131m\u0131.';\nString doubleQuote2 = \"\u00c7ift t\u0131rnak i\u00e7inde tekt\u0131rnak ' kullan\u0131m\u0131.\";\nString variableString = \"Tek t\u0131rnak yaz\u0131 \u00f6rne\u011fi: $singleQuote\";<\/code><\/pre>\n\n\n\nString multiLineSingleQuote = '''Tek t\u0131rnakl\u0131\n \t\t\t\t\t\t \u00c7oklu Sat\u0131r \u00f6rne\u011fidir''';\n \n String multiLineDoubleQuote = \"\"\"\u00c7ift t\u0131rnakl\u0131\n \t\t\t\t\t\t \u00c7oklu Sat\u0131r \u00f6rne\u011fidir\"\"\";\n\nString newLine = \"\u00c7ift t\u0131rnakl\u0131 \\n \u00c7oklu Sat\u0131r \u00f6rne\u011fidir\";\nString notNewLine = r\"\u00c7ift t\u0131rnakl\u0131 \\n \u00c7oklu Sat\u0131r \u00f6rne\u011fidir\";<\/code><\/pre>\n\n\n\nString longText = 'Tek satir'\n \t\t\t ' uzun yazi'\n \t\t\t \" b\u00f6lme \u00f6rne\u011fi\";\n\/\/ \u00c7\u0131kt\u0131: Tek satir uzun yazi b\u00f6lme \u00f6rne\u011fi<\/code><\/pre>\n\n\n\nbool isHidden = true;\nbool isHidden = false;<\/code><\/pre>\n\n\n\n\/\/ degisken turu int olan liste, farkli bir tur atanamaz.\nList<int> studentNumberList = [1233, 1231, 6543, 1236]; \n\n \/\/ degisken turu String olan liste, farkli bir tur atanamaz.\nList<String> alphabet = [\"a\", \"b\", \"c\"...];\n\n\/\/ var ifadesi ileriki sureclerde anlatilacaktir.\nvar differentType = [\"string\", 3, \"y\", false, 2.3];<\/code><\/pre>\n\n\n\n\/\/anahtar turu String, deger String turunde verileri tutan bir nesne\nMap<String, String> person = {'firstName': '\u0130zzet', 'lastName': '\u00d6zt\u00fcrk' };\n\n\/\/anahtar turu int, deger String turunde verileri tutan bir nesne\nMap<int, String> numbers = Map();\nnumbers[1] = \"one\";\nnumbers[2] = \"two\";\n\n\/\/ var ifadesi ileriki sureclerde anlatilacaktir.\nvar differentTypeMap = {\n 'key': false,\n 1: 'Deger',\n false: 3.32\n};<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"