#18 記法ミスの修正

lib/model/fruction.dart

@@ -1,97 +1,96 @@
 class Fruction {
-  int Numerator, Denominator;
-  Fruction(this.Numerator, this.Denominator) {
-    if (Denominator == 0) {
+  int numerator, denominator;
+  Fruction(this.numerator, this.denominator) {
+    if (denominator == 0) {
       throw ArgumentError("分母が0になっています");
-    } else if (Denominator < 0) {
-      Denominator *= -1;
-      Numerator *= -1;
+    } else if (denominator < 0) {
+      denominator *= -1;
+      numerator *= -1;
     }
-    Reduce();
+    reduce();
   }
 
   ///約分する
-  void Reduce() {
-    int gcd = Gcd(Numerator, Denominator);
-    Numerator = (Numerator / gcd).toInt();
-    Denominator = (Denominator / gcd).toInt();
+  void reduce() {
+    int _gcd = gcd(numerator, denominator);
+    numerator = numerator ~/ _gcd;
+    denominator = denominator ~/ _gcd;
   }
 
   @override
   String toString() {
-    return "$Numerator/$Denominator";
+    return "$numerator/$denominator";
   }
 
   ///最大公約数を求める
-  int Gcd(int a, int b) {
-    return ((a % b) == 0) ? b : Gcd(b, (a % b));
+  int gcd(int a, int b) {
+    return ((a % b) == 0) ? b : gcd(b, (a % b));
   }
 
   @override
   int get hashCode {
     var result = 3;
-    result = 31 * result + Numerator.hashCode;
-    result = 31 * result + Denominator.hashCode;
+    result = 31 * result + numerator.hashCode;
+    result = 31 * result + denominator.hashCode;
     return result;
     //return Object.hash(Numerator, Denominator);
   }
 
   //以下演算子のオーバーロード
-  Fruction operator +(dynamic a) {
-    if (a.runtimeType == Fruction) {
-      Fruction i = a;
-      return Fruction(Numerator * i.Denominator + i.Numerator * Denominator,
-          Denominator * i.Denominator);
-    } else if (a.runtimeType == int) {
-      int i = a;
-      return Fruction(Numerator + i * Denominator, Denominator);
+  Fruction operator +(other) {
+    if (other.runtimeType == Fruction) {
+      Fruction i = other;
+      return Fruction(numerator * i.denominator + i.numerator * denominator,
+          denominator * i.denominator);
+    } else if (other.runtimeType == int) {
+      int i = other;
+      return Fruction(numerator + i * denominator, denominator);
     } else {
       throw ArgumentError("無効な計算です");
     }
   }
 
-  Fruction operator -(dynamic a) {
-    if (a.runtimeType == Fruction) {
-      Fruction i = a;
-      return Fruction(Numerator * i.Denominator - i.Numerator * Denominator,
-          Denominator * i.Denominator);
-    } else if (a.runtimeType == int) {
-      int i = a;
-      return Fruction(Numerator - i * Denominator, Denominator);
+  Fruction operator -(other) {
+    if (other.runtimeType == Fruction) {
+      Fruction i = other;
+      return Fruction(numerator * i.denominator - i.numerator * denominator,
+          denominator * i.denominator);
+    } else if (other.runtimeType == int) {
+      int i = other;
+      return Fruction(numerator - i * denominator, denominator);
     } else {
       throw ArgumentError("無効な計算です");
     }
   }
 
-  Fruction operator *(dynamic a) {
-    if (a.runtimeType == Fruction) {
-      Fruction i = a;
-      return Fruction(i.Numerator * Numerator, i.Denominator * Numerator);
-    } else if (a.runtimeType == int) {
-      int i = a;
-      return Fruction(Numerator * i, Denominator);
+  Fruction operator *(other) {
+    if (other.runtimeType == Fruction) {
+      Fruction i = other;
+      return Fruction(i.numerator * numerator, i.denominator * numerator);
+    } else if (other.runtimeType == int) {
+      int i = other;
+      return Fruction(numerator * i, denominator);
     } else {
       throw ArgumentError("無効な計算です");
     }
   }
 
-  Fruction operator /(dynamic a) {
-    if (a.runtimeType == Fruction) {
-      Fruction i = a;
-      return Fruction(
-          this.Numerator * i.Denominator, this.Denominator * i.Numerator);
-    } else if (a.runtimeType == int) {
-      int i = a;
-      return Fruction(Numerator, Denominator * i);
+  Fruction operator /(other) {
+    if (other.runtimeType == Fruction) {
+      Fruction i = other;
+      return Fruction(numerator * i.denominator, denominator * i.numerator);
+    } else if (other.runtimeType == int) {
+      int i = other;
+      return Fruction(numerator, denominator * i);
     } else {
       throw ArgumentError("無効な計算です");
     }
   }
 
   @override
-  bool operator ==(dynamic a) {
-    return a is Fruction &&
-        a.Denominator == Denominator &&
-        a.Numerator == Numerator;
+  bool operator ==(other) {
+    return other is Fruction &&
+        other.denominator == denominator &&
+        other.numerator == numerator;
   }
 }

test/model/fraction_test.dart

@@ -1,20 +1,19 @@
-import 'dart:math';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:calculator2022/model/fruction.dart';
 
 void main() {
   test("fruction_and_fruction", () {
-    final A = Fruction(2, 3);
-    final B = Fruction(4, 3);
-    final result = A / B;
+    final a = Fruction(2, 3);
+    final b = Fruction(4, 3);
+    final result = a / b;
     final anser = Fruction(1, 2);
     expect(result, anser);
   });
 
   test("fructionfruction_and_int", () {
-    final A = Fruction(2, 3);
-    final B = 3;
-    final result = A / B;
+    final a = Fruction(2, 3);
+    const b = 3;
+    final result = a / b;
     Fruction anser = Fruction(2, 9);
     expect(result, anser);
   });