你不知道的js之原型链继承

　　　　　来来来，总结一波ES5的原型继承
        Function.__proto__ === Function.prototype //true   特殊
        
        Function.__proto__ === Object.__proto__  //true
        
        Object.__proto__.__proto__ === Object.prototype //true
        
        Array.__proto__ === Function.prototype   //true
        String.__proto__ === Function.prototype  //true
        Number.__proto__ === Function.prototype  //true
        Boolean.__proto__ === Function.prototype //true 
        
        (123).__proto__ === Number.prototype     //true会形成包装类,和new Number(123)一样
        ("123").__proto__ === String.prototype   //true
        (true).__proto__ === Boolean.prototype   //true
        ([]).__proto__ === Array.prototype       //true
        
        Number.prototype.__proto__ === Object.prototype  //true
        String.prototype.__proto__ === Object.prototype  //true
        Boolean.prototype.__proto__ === Object.prototype //true
        Array.prototype.__proto__ === Object.prototype   //true
        
        其实Number.prototype就是一个Object实例对象,而Object实例对象的__proto__指向Object.prototype
        
        ({}).__proto__ === Object.prototype  //true   特殊