Is There a way to Only Execute A line Of Code once?

[AyooNisto]

Is it possible to only execute a line of code once and skip over it every time it reads the code again?

[DarrylBurke]

You didn't bother to reply to the two responses in the first thread you started. Why should we expect any better behavior this time round?

db

[Chri]

I would do so

boolean check  = false;

public void onlyOnce(){
if(check == false){
//your code here
}
check = true;
}

so the first time the boolean will be false, and the code will be executed, and the other times the boolean will be true, and the code will be skipped ;)

[DarrylBurke]

if(check == false){

That's bad code.

db

[Chri]

That's bad code.

db

whoops, I always did so...
your post would be more useful if you would write the good code, wouldn't it?

[wsaryada]

You can simply write your code like:

if (!check) {
...
}

[AyooNisto]

I honestly forgot that I had made that thread I apologize for not responding to it.

You didn't bother to reply to the two responses in the first thread you started. Why should we expect any better behavior this time round?

db

[AyooNisto]

Thanks for the help guys but i should have been clearer in my original post, the problem that I am having is that within A method I need to create an ArrayList, the only problem is that when i call the method more then once it continually creates a new array list resetting the size of the array list to null each time, i need to be able to call the method without it clearing the array list so it can hold the values of the list each time when the method is called.

[wsaryada]

You can just convert the code above and use it in your scenario. You just need a condition when you will create the ArrayList and when not. For example check if the ArrayList is null or not. By knowing this condition you know whether you need to instantiate the ArrayList or not.

[pbrockway2]

within A method I need to create an ArrayList, the only problem is that when i call the method more then once it continually creates a new array list

I have trouble understanding this.

You say you "need" (=="have freely decided") to create an array list, but then say that it is problematic that the method does this very thing.

Perhaps you meant something like that you intend to create an array list under certain circumstances and not every time the method gets called, in which case that's precisely what you should do. In the discussion above these "certain circumstances" were illustrated with a boolean variable check, but anything your method can check will do: a common case is to check the value of the variable and only create an array list if it is null.

If this is all a bit vague, consider posting a code example: something brief, but compilable and runnable. Describe both what it does and what you intend its behaviour to be.

[Chri]

I think that if he surrounds the declaration of the arraylist with an if statement, any time he will try to use it outside the if statement he will get an error, cause the program don't know if the arraylist will exist or not (I'm not totally sure of what I'm saying, but trying I obtained this result)
EDIT: can't you simply create the arraylist outside the method?

[wsaryada]

The ArrayList can be declared as an instance variable of the class and the method will only contains the instantiation process of the ArrayList.