;
"use strict";
function IPoint() {
this.getDistance = function(point) {
var x = this.x - point.x;
var y = this.y - point.y;
return Math.sqrt(x * x + y * y);
};
this.isAbove = function(point) {
if (this.y <= point.y) {
return true;
} else {
return false;
}
};
this.isBelow = function(point) {
if (this.y >= point.y) {
return true;
} else {
return false;
}
};
this.isLeftOf = function(point) {
if (this.x <= point.x) {
return true;
} else {
return false;
}
};
this.isRightOf = function(point) {
if (this.x >= point.x) {
return true;
} else {
return false;
}
};
};
var Point = function(x, y) {
this.x = x;
this.y = y;
IPoint.call(this);
};
Point.prototype =
Object.create(null,
{
get x() {
return this._x;
},
set x(v) {
this._x = v;
},
get y() {
return this._y;
},
set y(v) {
this._y = v;
},
});
给我错误Uncaught TypeError: Property description must be an object: undefined geometry.js:47 (anonymous function)。这给我的印象是我不能在传递给 dot.create 的对象中使用 setter 和 getter,但我不知道为什么。我究竟做错了什么?