JS Private Methods
上一篇 /
下一篇 2015-08-15 14:16:09
/ 个人分类:JavaScript
Why did that code work? An object's private variables can only be accessed by other methods that are part of that same object. So, we just used an object's public method to access a private variable!
Methods can also be private within a class and inaccessible outside of the class. Changing this.returnBalance
from the last exercise to varreturnBalance
makes this method private. If you run the program trying to access the method you get an undefined
error this time.
The way to access a private method is similar to accessing a private variable. You must create a public method for the class that returns the private method.
Create a method called askTeller
within the Person
class that returns the returnBalance
method. This means that it returns the method itself and NOT the result of calling that method. So you should NOT have parentheses after returnBalance
.
Because askTeller
returns a method, we need to call it to make it any use. This is what var myBalance = myBalanceMethod();
does.
?
Hint
Your method should resemble how we defined getBalance
last time—you should use this.askTeller = function() { }
. Don't declare askTeller
with var
.
You return method the same way that you would return simple variables. Be careful not to call the method though and leave out parentheses in your return statement!
收藏
举报
TAG: