JavaScript 函數的引用傳遞

先看代碼:

	window.color = "red";
	var o = { color : "blue" };

	function sayColor(){
		alert(this.color);
	}

	sayColor();

	o.sayColor = sayColor;
	o.sayColor();

結果:

1. red 
2. blue

若修改sayColor()函數 則全部受影響

	window.color = "red";
	var o = { color : "blue" };

	function sayColor(){
		alert(this.color);
	}

	sayColor();

	o.sayColor = sayColor;
	o.sayColor();

	function sayColor(){
		alert("wobianle");
	}

	o.sayColor();

結果:

1. wobianle
2. wobianle
3. wobianle

若對o.sayColor()函數進行修改,則隻影響o的sayColor()函數

window.color = "red";
	var o = { color : "blue" };

	function sayColor(){
		alert(this.color);
	}

	sayColor();

	o.sayColor = sayColor;
	o.sayColor();


	o.sayColor = function(){
		alert("wobianle");
	}

	o.sayColor();

結果:

1. red
2. blue
3. wobianle