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Why is volatile not considered useful in multithreaded C or C++ programming?
...roblem with volatile in a multithreaded context is that it doesn't provide all the guarantees we need. It does have a few properties we need, but not all of them, so we can't rely on volatile alone.
However, the primitives we'd have to use for the remaining properties also provide the ones that vol...
Question mark and colon in JavaScript
...
It is called the Conditional Operator (which is a ternary operator).
It has the form of: condition ? value-if-true : value-if-false
Think of the ? as "then" and : as "else".
Your code is equivalent to
if (max != 0)
hsb.s = 255 ...
How to tell if UIViewController's view is visible
... be better to check first to see if it is already loaded. I've added the call to isViewLoaded to avoid this problem.
if (viewController.isViewLoaded && viewController.view.window) {
// viewController is visible
}
Since iOS9 it has became easier:
if viewController.viewIfLoaded?.windo...
Open new Terminal Tab from command line (Mac OS X)
...egistry as CLI ttab, which also supports iTerm2:
If you have Node.js installed, simply run:
npm install -g ttab
(depending on how you installed Node.js, you may have to prepend sudo).
Otherwise, follow these instructions.
Once installed, run ttab -h for concise usage information, or man ttab to...
Initial size for the ArrayList
...lements in the list;
the capacity is how many elements the list can potentially accommodate without reallocating its internal structures.
When you call new ArrayList<Integer>(10), you are setting the list's initial capacity, not its size. In other words, when constructed in this manner, the ...
How to differ sessions in browser-tabs?
...f I store information in the user session, this information is shared from all the tabs from the same browser. How to differ sessions in the browser-tabs?
In this example:
...
Finding the direction of scrolling in a UIScrollView?
I have a UIScrollView with only horizontal scrolling allowed, and I would like to know which direction (left, right) the user scrolls. What I did was to subclass the UIScrollView and override the touchesMoved method:
...
Android: How to change the ActionBar “Home” Icon to be something other than the app icon?
...worked great. No need to mess with a custom theme or worry about affecting all the activities.
– Jason
Sep 20 '13 at 21:56
...
npm WARN package.json: No repository field
I installed Express.js with the following command:
11 Answers
11
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Why are arrays covariant but generics are invariant?
...e array, so it should be possible to write a single function that works on all types of arrays. It is easy to implement functions of type
boolean equalArrays (Object[] a1, Object[] a2);
void shuffleArray(Object[] a);
However, if array types were treated as invariant, it would only be possible...