Shout out to our very own Tosha Shah for representing Texas and NIC at the myAmerica Developer Summit hackathon hosted...

Posted by Texas.gov on Friday, April 17, 2015

Salesforce Iwatch webinar

The Apple Watch is the long anticipated wearable device from Apple. It includes a striking design and innovative new interface. Developers can build apps, or specifically extensions to apps running on their iPhone, using WatchKit, Apple’s developer SDK. Now, with the latest Salesforce Wear Developer Pack developers can build apps for Apple Watch and Salesforce.com Join this webinar to learn how to build your first Apple Watch app using Salesforce Wear Kit.

What you will learn:
 

• How to use the Salesforce Wear Developer Pack to extend your iPhone apps to the Apple Watch

• Common implementation patterns for Apple Watch development, including: notifications, glances, messaging with the Salesforce Mobile SDK of iOS delegates, and more

• Storyboards and project targets for xCode and Apple Watch

• Writing Swift code to work with Salesforce data

 

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Key Takeaways

• How to create an Apple Watch app in conjunction with the Salesforce Mobile SDK for iOS

• Sending and receiving data from Salesforce on the Apple Watch

 

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Intended Audience

 

Existing Apple iOS developers, or Salesforce Platform developers interested in getting started with iOS Development

Java Questions

Does Java pass by reference or pass by value?

 

Q: If Java uses the pass-by reference, why won't a swap function work?
A: Java does manipulate objects by reference, and all object variables are references. However, Java doesn't pass method arguments by reference; it passes them by value.
Take the badSwap() method for example:

public void badSwap(int var1, int var2)
{
  int temp = var1;
  var1 = var2;
  var2 = temp;
}

When badSwap() returns, the variables passed as arguments will still hold their original values. The method will also fail if we change the arguments type from int to Object, since Java passes object references by value as well. Now, here is where it gets tricky:

public void tricky(Point arg1, Point arg2)
{
  arg1.x = 100;
  arg1.y = 100;
  Point temp = arg1;
  arg1 = arg2;
  arg2 = temp;
}
public static void main(String [] args)
{
  Point pnt1 = new Point(0,0);
  Point pnt2 = new Point(0,0);
  System.out.println("X: " + pnt1.x + " Y: " +pnt1.y); 
  System.out.println("X: " + pnt2.x + " Y: " +pnt2.y);
  System.out.println(" ");
  tricky(pnt1,pnt2);
  System.out.println("X: " + pnt1.x + " Y:" + pnt1.y); 
  System.out.println("X: " + pnt2.x + " Y: " +pnt2.y);  
}

If we execute this main() method, we see the following output:

X: 0 Y: 0
X: 0 Y: 0
X: 100 Y: 100
X: 0 Y: 0

The method successfully alters the value of pnt1, even though it is passed by value; however, a swap of pnt1 and pnt2 fails! This is the major source of confusion. In the main() method, pnt1 and pnt2 are nothing more than object references. When you pass pnt1 and pnt2 to the tricky() method, Java passes the references by value just like any other parameter. This means the references passed to the method are actually copies of the original references. Figure 1 below shows two references pointing to the same object after Java passes an object to a method.

Figure 1. After being passed to a method, an object will have at least two references

Java copies and passes the reference by value, not the object. Thus, method manipulation will alter the objects, since the references point to the original objects. But since the references are copies, swaps will fail. As Figure 2 illustrates, the method references swap, but not the original references. Unfortunately, after a method call, you are left with only the unswapped original references. For a swap to succeed outside of the method call, we need to swap the original references, not the copies.

Figure 2. Only the method references are swapped, not the original ones

O'Reilly's Java in a Nutshell by David Flanagan (see Resources) puts it best: "Java manipulates objects 'by reference,' but it passes object references to methods 'by value.'" As a result, you cannot write a standard swap method to swap objects.

Tony Sintes is a principal consultant at BroadVision. Tony, a Sun-certified Java 1.1 programmer and Java 2 developer, has worked with Java since 1997.

 

 

Source: http://www.javaworld.com/article/2077424/learn-java/does-java-pass-by-reference-or-pass-by-value.html