visual basic barcode printing 8: Inner Classes in Java

Generating PDF-417 2d barcode in Java 8: Inner Classes

8: Inner Classes
Read PDF 417 In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
PDF417 Creation In Java
Using Barcode maker for Java Control to generate, create PDF417 image in Java applications.
(say, an instance method) can access any other member of the outer class, private or not, the inner class also a member can do the same. OK, so now that we know how to write the code giving an inner class access to members of the outer class, how do you actually use it
PDF-417 2d Barcode Recognizer In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Barcode Encoder In Java
Using Barcode printer for Java Control to generate, create bar code image in Java applications.
Instantiating an Inner Class
Barcode Scanner In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
Paint PDF-417 2d Barcode In C#
Using Barcode drawer for Visual Studio .NET Control to generate, create PDF417 image in Visual Studio .NET applications.
To instantiate an instance of an inner class, you must have an instance of the outer class to tie to the inner class. There are no exceptions to this rule; an inner class instance can never stand alone without a direct relationship with a specific instance of the outer class. Instantiating an Inner Class from Within Code in the Outer Class Most often, it is the outer class that creates instances of the inner class, since it is usually the outer class wanting to use the inner instance as a helper object, for it s own personal, private use. We ll modify the MyOuter class to instantiate an instance of MyInner:
PDF 417 Creation In Visual Studio .NET
Using Barcode generation for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
Generating PDF-417 2d Barcode In .NET Framework
Using Barcode creator for .NET Control to generate, create PDF-417 2d barcode image in .NET applications.
class MyOuter { private int x = 7; public void makeInner() { MyInner in = new MyInner(); in.seeOuter(); } class MyInner { public void seeOuter() { System.out.println("Outer x is " + x); } } }
PDF-417 2d Barcode Generation In VB.NET
Using Barcode drawer for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in VS .NET applications.
Create EAN13 In Java
Using Barcode encoder for Java Control to generate, create GS1 - 13 image in Java applications.
You can see in the preceding code that the MyOuter code treats MyInner just as though MyInner were any other accessible class it instantiates it using the class name (new MyInner()), and then invokes a method on the reference variable (in.seeOuter()). But the only reason this syntax works is because the outer class instance method code is doing the instantiating. In other words, there s already an instance of the outer class the instance running the makeInner() method. So
Matrix Barcode Printer In Java
Using Barcode creation for Java Control to generate, create Matrix Barcode image in Java applications.
Create Code 3/9 In Java
Using Barcode generation for Java Control to generate, create ANSI/AIM Code 39 image in Java applications.
Inner Classes
Identcode Encoder In Java
Using Barcode drawer for Java Control to generate, create Identcode image in Java applications.
EAN / UCC - 13 Creator In VS .NET
Using Barcode encoder for .NET framework Control to generate, create EAN / UCC - 13 image in .NET framework applications.
how do you instantiate a MyInner object from somewhere outside the MyOuter class Is it even possible (Well, since we re going to all the trouble of making a whole new subhead for it, as you ll see next, there s no big mystery here.) Creating an Inner Class Object from Outside the Outer Class Instance Code Whew. Long subhead there, but it does explain what we re trying to do. If we want to create an instance of the inner class, we must have an instance of the outer class. You already know that, but think about the implications it means you can t instantiate the inner class from a static method of the outer class (because, don t forget, in static code there is no this reference) or from any other code in any other class. Inner class instances are always handed an implicit reference to the outer class. The compiler takes care of it, so you ll never see anything but the end result the ability of the inner class to access members of the outer class. The code to make an instance from anywhere outside nonstatic code of the outer class is simple, but you must memorize this for the exam!
EAN13 Creator In Java
Using Barcode drawer for Android Control to generate, create EAN13 image in Android applications.
Encoding UPC-A Supplement 5 In .NET
Using Barcode creation for ASP.NET Control to generate, create UCC - 12 image in ASP.NET applications.
public static void main (String[] args) { MyOuter mo = new MyOuter(); MyOuter.MyInner inner = mo.new MyInner(); inner.seeOuter(); }
Barcode Encoder In Objective-C
Using Barcode creator for iPhone Control to generate, create bar code image in iPhone applications.
Generate ECC200 In None
Using Barcode maker for Word Control to generate, create Data Matrix ECC200 image in Word applications.
The preceding code is the same regardless of whether the main() method is within the MyOuter class or some other class (assuming the other class has access to MyOuter, and since MyOuter has default access, that means the code must be in a class within the same package as MyOuter). If you re into one-liners, you can do it like this:
DataMatrix Recognizer In C#
Using Barcode decoder for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Create Linear 1D Barcode In .NET
Using Barcode generator for ASP.NET Control to generate, create 1D Barcode image in ASP.NET applications.
public static void main (String[] args) { MyOuter.MyInner inner = new MyOuter().new MyInner(); inner.seeOuter(); }
You can think of this as though you re invoking a method on the outer instance, but the method happens to be a special inner class instantiation method, and it s invoked using the keyword new. Instantiating an inner class is the only scenario in which you ll invoke new on an instance as opposed to invoking new to construct an instance.
Copyright © OnBarcode.com . All rights reserved.