该图再次显示每个对象都有一个原型.构造函数Foo也有自己
__proto__的Function.prototype,它又通过其__proto__属性再次引用到Object.prototype.因此,重复,Foo.prototype只是Foo的一个显式属性,它指的是b和c对象的原型.
var b = new Foo(20);
var c = new Foo(30);
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__proto__和prototype属性有什么区别?

这个数字来自这里.
javascript prototype prototypal-inheritance javascript-objects
所以我有这两个例子,来自javascript.info:
例1:
var animal = {
eat: function() {
alert( "I'm full" )
this.full = true
}
}
var rabbit = {
jump: function() { /* something */ }
}
rabbit.__proto__ = animal
rabbit.eat()
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例2:
function Hamster() { }
Hamster.prototype = {
food: [],
found: function(something) {
this.food.push(something)
}
}
// Create two speedy and lazy hamsters, then feed the first one
speedy = new Hamster()
lazy = new Hamster()
speedy.found("apple")
speedy.found("orange")
alert(speedy.food.length) // 2
alert(lazy.food.length) // 2 (!??)
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从示例2开始:当代码到达时 …