this.nativeTo = function () {
this.nativeToLand.forEach(function (eachCountry) {
console.log("Grown in:" + eachCountry);
});
}
}

// 现在，可以调用printStuff方法
aMango.printStuff();

Fruit.prototype.showName = function () {
console.log("This is a " + this.fruitName);
}

Fruit.prototype.nativeTo = function () {
console.log("Grown in:" + this.nativeToLand);
}

​// 打印出true，因为对象拥有schoolName这个属性
console.log("schoolName" in school); // true​
​
​// 打印出false，因为我们既没有定义schoolType属性，也没有从Object的Prototype中继承schoolType属性
console.log("schoolType" in school); // false​

​// 打印出true,因为从Object的Prototype中继承了toString方法
console.log("toString" in school); // true

​// 打印出false，因为toString是从Object的Prototype中继承下来的，并且school的自身属性
console.log(school.hasOwnProperty ("toString")); // false

// 注：以下这段说明是原文的说明
/ SIDE NOTE: As Wilson (an astute reader) correctly pointed out in the comments below,the educationLevel property is not actually inherited by objects that use the HigherLearning constructor; instead,the educationLevel property is created as a new property on each object that uses the HigherLearning constructor. The reason the property is not inherited is because we use of the "this" keyword to define the property.
/​

// Create a new HigherLearning function that the school object will inherit from.​

function HigherLearning () {
this.educationLevel = "University";
}

// Implement inheritance with the HigherLearning constructor​
var school = new HigherLearning ();
school.schoolName = "MIT";
school.schoolAccredited = true;
school.schoolLocation = "Massachusetts";

//Use of the for/in loop to access the properties in the school object​
for (var eachItem in school) {
console.log(eachItem); // Prints educationLevel,schoolName,and schoolLocation​
}

delete christmasList.toString; // 返回 true,但是因为toString是继承的属性，所以它不会被删除

// 因为toString没有被删除，所以这里还能够正常使用
christmasList.toString(); //"[object Object]"​

// 如果一个属性是对象实例的自身属性，则我们可以删除它。
// 比如我们可以从之前例子中定义的school对象中删除educationLevel属性，
// 因为educationLevel是定义在那个实例中的：我们在HigherLearning函数中定义educationLevel时使用了"this"关键字。
//我们并没有在HigherLearning函数的prototype对象在定义educationLevel属性。

console.log(school.hasOwnProperty("educationLevel")); // true​
// educationLevel是一个school对象的一个自身属性，所以 我们可以删除它​
delete school.educationLevel; // true

// educationLevel属性已经从school实例中删除了
console.log(school.educationLevel); // undefined

// 但是educationLevel属性仍然存在于HigherLearning函数中
var newSchool = new HigherLearning ();
console.log(newSchool.educationLevel); // University​

// 如果我们在HigherLearning函数prototype中定义了一个属性,比如这个educationLevel2属性:​
HigherLearning.prototype.educationLevel2 = "University 2";

// 这个educationLevel2属性不属性HigherLearning实例的自身属性

// educationLevel2属性不是school实例的自身属性​
console.log(school.hasOwnProperty("educationLevel2")); false​
console.log(school.educationLevel2); // University 2​

// 尝试删除继承的educationLevel2属性​
delete school.educationLevel2; // true (正如前面所提到的，这个表达式会返回true)

// 继承的educationLevel2属性没有被删除
console.log(school.educationLevel2); University 2​

// JSON.parse Examples
// The following is a JSON string,so we cannot access the properties with dot notation (like christmasListStr.mike)​
var christmasListStr = '{"mike":"Book","chels":"iPad"}';

// Let's convert it to an object​
var christmasListObj = JSON.parse (christmasListStr);

// Now that it is an object,we use dot notation​
console.log(christmasListObj.mike); // Book

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