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Why is the String class declared final in Java?
...emented as immutable objects. You should read about immutability to understand more about it.
One advantage of immutable objects is that
You can share duplicates by pointing them to a single instance.
(from here).
If String were not final, you could create a subclass and have two strings tha...
Difference between numpy.array shape (R, 1) and (R,)
...ning of shapes in NumPy
You write, "I know literally it's list of numbers and list of lists where all list contains only a number" but that's a bit of an unhelpful way to think about it.
The best way to think about NumPy arrays is that they consist of two parts, a data buffer which is just a block...
Hidden Features of Java
...e per-thread state.
Since JDK 1.5 Java has had extremely well implemented and robust concurrency tools beyond just locks, they live in java.util.concurrent and a specifically interesting example is the java.util.concurrent.atomic subpackage that contains thread-safe primitives that implement the co...
Why is Magento so slow? [closed]
...g, layout config, etc.) that involve building up giant XML trees in memory and then "querying" those same trees for information. This takes both memory (storing the trees) and CPU (parsing the trees). Some of these (especially the layout tree) are huge. Also, unless caching is on, these tree are ...
Is it possible to use Visual Studio on macOS?
...hich also now supports debugging. Thus, if you install Visual Studio Code and .NET Core on a Mac in OS X you can quite freely edit and compile and run and debug and share your code with Visual Studio 2017 on a PC.
– DavidMWilliams
Feb 2 '17 at 5:16
...
How to sort an array in Bash
...set IFS
Supports whitespace in elements (as long as it's not a newline), and works in Bash 3.x.
e.g.:
$ array=("a c" b f "3 5")
$ IFS=$'\n' sorted=($(sort <<<"${array[*]}")); unset IFS
$ printf "[%s]\n" "${sorted[@]}"
[3 5]
[a c]
[b]
[f]
Note: @sorontar has pointed out that care is re...
Android List View Drag and Drop sort
...ords in a listview that I want the user to be able to re-sort using a drag and drop method. I have seen this implemented in other apps, but I have not found a tutorial for it. It must be something that others need as well. Can anyone point me to some code for doing this?
...
How to get existing fragments when using FragmentPagerAdapter
...entPagerAdapter , as a helper class that implements the management of tabs and all details of connecting a ViewPager with associated TabHost . I have implemented FragmentPagerAdapter just as same as it is provided by the Android sample project Support4Demos .
...
What Makes a Good Unit Test? [closed]
I'm sure most of you are writing lots of automated tests and that you also have run into some common pitfalls when unit testing.
...
Comparing date part only without comparing time in JavaScript
...
I'm still learning JavaScript, and the only way that I've found which works for me to compare two dates without the time is to use the setHours method of the Date object and set the hours, minutes, seconds and milliseconds to zero. Then compare the two dat...