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Why does my application spend 24% of its life doing a null check?
...t store a copy of the bytes in RAM. An important one is the L1 cache, typically 16 kilobytes for data and 16 kilobytes for instructions. Small, allowing it to be close to the execution engine. Reading bytes from the L1 cache typically takes 2 or 3 CPU cycles. Next up is the L2 cache, bigger and slow...
How can I echo HTML in PHP?
I want to conditionally output HTML to generate a page, so what's the easiest way to echo multiline snippets of HTML in PHP 4+? Would I need to use a template framework like Smarty?
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Error type 3 Error: Activity class {} does not exist
...the Build directory
Restarted Android Studio
Rebuild the Project
Run
Optionally (Go to the files menu on android, click on "Invalidate Caches / Restart..." uninstall the app on your phone and try again)
And everything worked fine!
I think the key is to restart your IDE.
Hope this helps you or a...
PDO MySQL: Use PDO::ATTR_EMULATE_PREPARES or not?
...er using the binary protocol. In other words, the same PDO code will be equally vulnerable (or not-vulnerable) to injection attacks regardless of your EMULATE_PREPARES setting. The only difference is where the parameter replacement occurs--with EMULATE_PREPARES, it occurs in the PDO library; without...
I do not want to inherit the child opacity from the parent in CSS
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Opacity is not actually inherited in CSS. It's a post-rendering group transform. In other words, if a <div> has opacity set you render the div and all its kids into a temporary buffer, and then composite that whole buffer into the page ...
Update R using RStudio
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You install a new version of R from the official website.
RStudio should automatically start with the new version when you relaunch it.
In case you need to do it manually, in RStudio, go to :Tools -> options -> General.
Chec...
Are (non-void) self-closing tags valid in HTML5?
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In HTML 4, <foo / (yes, with no > at all) means <foo> (which leads to <br /> meaning <br>> (i.e. <br>&gt;) and <title/hello/ meaning <title>hello</title>). This is an SGML rule that browsers did a very poor job of su...
How many bytes does one Unicode character take?
...ing, it defines codepoints and a codepoint is a number, associated with usually a character. I say usually because there are concepts like combining characters. You may be familiar with things like accents, or umlauts. Those can be used with another character, such as an a or a u to create a new log...
Why does Apple recommend to use dispatch_once for implementing the singleton pattern under ARC?
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dispatch_once() is absolutely synchronous. Not all GCD methods do things asynchronously (case in point, dispatch_sync() is synchronous). The use of dispatch_once() replaces the following idiom:
+ (MyClass *)sharedInstance {
static MyClass *sharedInstance;
@synchr...
Elements order in a “for (… in …)” loop
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Quoting John Resig:
Currently all major browsers loop over the properties of an object in the order in
which they were defined. Chrome does this as well, except for a couple cases. [...]
This behavior is explicitly left undefined by the ECMAScript specifi...