Make a Person
Fill in the object constructor with the following methods below:
getfirstname() getLastName() getFullName() setFirstName(first) setLastName(last) setFullName(firstAndLast)Run the tests to see the expected output for each method.
The methods that take an argument must accept only one argument and it has to be a string.
These methods must be the only available means of interacting with the object.
考察闭包
直接上代码好了
let Person = function(firstAndLast) {
let firstName, lastName;
this.getFirstName = () => firstName;
this.getLastName = () => lastName;
this.getFullName = () => firstName + ' ' + lastName;
this.setFirstName = first => firstName = first;
this.setLastName = last => lastName = last;
this.setFullName = firstAndLast => {
firstAndLast = firstAndLast.split(' ');
firstName = firstAndLast[0];
lastName = firstAndLast[1];
};
this.setFullName(firstAndLast);
};
这里要注意的是this的使用。上述代码中，只有6个方法使用了this。
firstName, lastName不使用this是为了防止Person的实例直接访问。
要真正实现私有属性，一种方式是使用闭包。即使这样做会增加资源占用。
要想访问或设置firstName, lastName，必须使用给定的方法。
下面是运行结果图。
Make-a-Person.png
