variable « performance « Java Testing Q&A

1. Choosing when to instantiate classes    stackoverflow.com

I recently wrote a class for an assignment in which I had to store names in an ArrayList (in java). I initialized the ArrayList as an instance variable private ArrayList<String> names. ...

2. Performance: Single Variable Assignment vs Objectgraph Navigation (Java)    stackoverflow.com

my question is about two possible ways to access data: (My question is about "real life usage" of java statements like below, accessing the data 2-10 times in a function. Not ...

3. Java Method invocation vs using a variable    stackoverflow.com

Recently I got into a discussion with my Team lead about using temp variables vs calling getter methods. I was of the opinion for a long time that, if I know ...

4. Where are Java final local variables stored?    stackoverflow.com

Take the following example:

public void init() {
    final Environment env = new Environment();
    Runtime.getRuntime().addShutdownHook(new Thread() {
        public void ...

5. GetPropertyAction vs System.getProperty in obtaining system variables    stackoverflow.com

I have been using quite a lot of

System.getProperty("property")

(String) java.security.AccessController.doPrivileged(
      ...

6. Performance of variable argument methods in Java    stackoverflow.com

I have this question about the performance of a method in Java with a variable number of parameters. Say I have the following 2 alternatives:

public static final boolean isIn(int i, int v1, ...

7. Does adding local variables to methods make them slower?    stackoverflow.com

This question has received a total of several paragraphs of answer. Here is the only sentence that actually tells me what I was looking for:

Your examples would make little ...

8. Need to know which method of variable handling would be more efficient in this case    stackoverflow.com

Right now I have a config reader class which goes through a text config file and adds values it finds to variables I have declared earlier. Then all these variables are ...

9. Is using variables from other classes slower than variables within the same class?    stackoverflow.com

I'm making a game, and I recently organized all the code. For drawing, I now use variables from another class, and I noticed a quite important performance decrease at the time of ...

10. Speed: four ints or one int with many operations    stackoverflow.com

I have a speed question for Java. I am making a chess program, and I want to check if is a good idea to use one 'int' as a variable to ...

11. Whether Using final With Local Variable Will Increase Performance?    coderanch.com

The general rule that most programmers SHOULD live by is this: Write code that makes sense, that does what you need, and is simple. ONLY then, if you have a performance issue, should you consider optimizing it. and then, use a tool to find out where the slowdowns are. 99.9% of the time, the slowdown is somewhere you are not looking, ...

12. Temporary variables and performance    forums.oracle.com

s_h_a_k wrote: If I wrote the code above as the one below would that make any considerable difference. No. Which one would be a better programming practice? Is anything written about it? [Writing Better Code: A Conversation With Sun Microsystems Technology Evangelist Brian Goetz|http://java.sun.com/developer/technicalArticles/Interviews/goetz_qa.html] Q: So how can developers write Java code that performs well? A: The answer may seem counterintuitive. ...

13. performance issue related to Wrapper and variable value retrievel    forums.oracle.com

If I have a array of int(primitive array) and on the other hand if I have an array of it's corresponding Wrapper class , while dealing is there is any performance difference betwen these 2 cases . If in my code I am doing to conversion from primitive to wrapper object , is that affecting my performnace as there is already ...

14. Doubt about performance in declaring variables    forums.oracle.com