swift 运算符重载

定义坐标点类

class Point{
    var x:Float!
    var y:Float!
    init(x:Float,y:Float){
        self.x=x
        self.y=y
    }
}

重载加减运算符

func +(p1:Point,p2:Point) -> Point {
    return Point(x: p1.x+p2.x,y: p1.y+p2.y)
}

func -(p1:Point,p2:Point) -> Point {
    return Point(x: p1.x-p2.x,y: p1.y-p2.y)
}

测试案例

var p1=Point(x: 1,y: 2)
var p2=Point(x: 3,y: -5)
p1=p1+p2
print(p1.x,p1.y)
p1=p1-p2
print(p1.x,p1.y)

输出

4.0 -3.0
1.0 2.0