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April 24, 2022 08:59 pm GMT

Dart Typing

Dart, tip kontroln iki farkl zamanda gerekletirir:
Kod derlendiinde (kod yeniden yklenir/veya nceden derlenir).
Kod altrldnda (runtime).

Static Tipler

int: Tamsaylar
double: Ondalk saylar(ift hassasiyet)
bool: Boolean true ya da false
String : Immutable (deimez) string
StringBuffer: Mutable(deiken) string
RegExp: Dzenli ifadeler
List, Map, Set: Koleksiyon class'lar
DateTime
Duration: Bir zaman aral
Uri: Identifier
Error: Hata bilgisi

Dynamic Tipler (aka Untyped)

Tr bilgisi olmayan deikenleri var veya dynamic anahtar kelimelerini kullanarak tanmlayabilirsiniz.

kisinin arasnda ince bir fark vardr:

void main() {print (multiplyMethod1(2,4));print (multiplyMethod2(2,4));}dynamic multiplyMethod1(int a, int b){return a * b;}var multiplyMethod2(int a, int b){return a * b;}

Bu kodu derlemeye altnzda aadaki hatay alrsnz:

Error compiling to JavaScript: main.dart:10:1: Error: The return type can't be 'var'. var multiplyMethod2(int a, int b){ ^^^ Error: Compilation failed.

Bunun nedeni methodlarn bir tr dndrmesi gerekmesi ve var dndrememesidir. Bir tr belirtmeniz gerekir.

Tip karm (Type Inference)
rnek 1:

void main() {dynamic x = 1;if (x is int){print('integer');}}

Output:

integer

rnek 2:

void main() {dynamic x = 'test';if (x is String){print('String');}x += 1;}

Output:

String Uncaught exception: TypeError: 1: type 'JSInt' is not a subtype of type 'String'

Tip Eletirme

Dart, kullanclarn 'is' anahtar szcn kullanarak tipleri kontrol etmesine olanak tanr.

main(){printType(23);printType('mark');}printType(dynamic d){if (d is int){print ('Its an Integer');}if (d is String){print ('Its a String');}}

Output:

Its an IntegerIts a String

Tip Bilgileri

alma zamannda runtimeType zelliini kullanarak bir nesnenin tipine eriebilirsiniz.

void main() {var v1 = 10;print(v1.runtimeType);var v2 = 'hello';print(v2.runtimeType);}

kt:

intString

Resource: Learn Google Flutter Fast - Mark Clow


Original Link: https://dev.to/gulsenkeskin/dart-typing-74k

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