Different ways to initiate an object

[Angelica Maria]

Hello,
Here is my code

Public void execution() {
	 op = new op;
}
 
Public getOperation(){
	return op;
}

It works in case I call the method executionToto2 and if execution, I have a NullPointerException. I do not, the Operation class will be declared "private" and I want to access this class by Get ... which is public. I want to know how may ways are there to initiate a object. Any help on this will be appreciated. Thanks in advance.

[HardWeaR]

Hello,
I think this is called as a local variable which you have used in your code

op op

mask operation attribute in your class. I think you should do some study on the basics of the java that is the core java. If you need a help on this and that to in simple way you can visit the official site of the sun and there you can find more detailed information on this and also know the api which are used in java.

[InterNetWorKed]

Hello,
In this case, your method returns nothing. You created an instance of a class that will be used throughout the life of the civil execution(). In this method so you created an instance of Operation that you registered in a local variable named operation (PS: your NullPointerException must come from the fact that there is a naming conflict because when compiling, it found that 2 variables for the compiler are different but have the same name). I hope this will help you.

[SoftWore]

Hello,
Yes, I completely agree with the above post and here is a sample example to explain the same.

/ / Declaration of class op
private op op;

Public void execution2 () (
 op = new op ();
)

Public getOperation () (
 return op;
)

In this case, you created a global variable called operation, it has a lifetime equivalent to the instance of the class that contains it. Here, if you do not pass through the execution function () getOperation () returns null because it is the default value that will take your global variable so that you do not instantiate.

[Angelica Maria]

Hello,
So the best thing to do is?:

/ / Declaration of class op
private op op;

Code:

Public void execution() {
	 op = new op;
}

Code:

Public getOperation(){
	return op;
}

I guess I am correct here, if I am wrong somewhere in the code, then guide me with the correct. Thanks in advance.

[Linux-Us]

Hello,
I think you can do the following

Public getOperation () (
return op;
}

But also this

public op getOperation () (
 return op;
)

I hope this will help you and you have understood the concept behind it.