@override bool operator ==(dynamic other) { if (other is! Testoperator) return false; Testoperator person = other; return (person.x == x && person.y == y); } } 4.noSuchMethod() 要在代码尝试使用不存在的方法或实例变量时检测或做出反应,
classSquare{double?width;double?height;Square({required double width,required double height}){this.width=width<0?0:width;this.height=height<0?0:height;}/// 返回类型可写可不写,dart会自动推断!@overrideSquareoperator+(Squaresquare){varw=(this.width??0)+(square.width??0);//宽加宽varh=(this...
*/Vector operator+(Vector v)=>Vector(x+v.x,y+v.y);Vector operator-(Vector v)=>Vector(x-v.x,y-v.y);/* 1,覆盖==符号,必须也好覆盖hashCode方法 */@override intgethashCode{int res=1;res=res+x.hashCode;res=res+y.hashCode;returnres}@override bool operator==(dynamic other){if(other ...
score); bool operator ==(Vip other) => level == other.level && score == other.level; //注意: 这段代码可能在高版本的Dart中会报错,在低版本是OK的 //上述代码,在高版本Dart中,Object中已经重载了==,所以需要加上covariant关键字重写这个重载函数。 @override bool operator ==(covariant Vip ...
class Vector { final int x, y; Vector(this.x, this.y); Vector operator +(Vector v) => Vector(x + v.x, y + v.y); Vector operator -(Vector v) => Vector(x - v.x, y - v.y); @override bool operator ==(Object other) => other is Vector && x == other.x && y == ...
class Vector { final int x, y; Vector(this.x, this.y); Vector operator +(Vector v) => Vector(x + v.x, y + v.y); Vector operator -(Vector v) => Vector(x - v.x, y - v.y); @override bool operator ==(Object other) => other is Vector && x == other.x && y == ...
在dart 中如果要判断一个对象的是否相等需要复写operator ==和hashCode。总是这样的代码很无趣也没有效率。比如 要判断 两个 Person 对象是否相等,需要这样写 class Person {const Person(this.name);final String name;@overridebool operator ==(Object other) =>identical(this, other) ||other is Person &&...
T operator [](int index) => index < _list.length ? _list[index] : absentValue; @override void operator []=(int index, T value) => _list[index] = value; @override int get length => _list.length; @override T get first => _list.isNotEmpty ? _list.first : absentValue; ...
classVector{finalintx, y;Vector(this.x,this.y);Vectoroperator+(Vector v) => Vector(x + v.x, y + v.y);Vectoroperator-(Vector v) => Vector(x - v.x, y - v.y);@overridebooloperator==(Objecto) => oisVector && x == o.x && y == o.y;}voidmain() {finalv = Vector(2...
operator true async do for part try async* dynamic get rethrow typedef await else if return var break enum implements set void case export import static while catch external in super with class extends is switch yield const factory library ...