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Mathematical functions in Swift
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UIKit, Cocoa, Foundation, all valid choices.
– erdekhayser
Nov 27 '14 at 20:26
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What does the PHP error message “Notice: Use of undefined constant” mean?
...l_escape_string($_POST['message']);
As is, it was looking for constants called department, name, email, message, etc. When it doesn't find such a constant, PHP (bizarrely) interprets it as a string ('department', etc). Obviously, this can easily break if you do defined such a constant later (tho...
How to remove non-alphanumeric characters?
I need to remove all characters from a string which aren't in a-z A-Z 0-9 set or are not spaces.
9 Answers
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When to use self over $this?
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$x = new Y();
$x->bar();
?>
The idea is that $this->foo() calls the foo() member function of whatever is the exact type of the current object. If the object is of type X, it thus calls X::foo(). If the object is of type Y, it calls Y::foo(). But with self::foo(), X::foo() is always ...
Unit testing that events are raised in C# (in order)
...ited May 12 '11 at 15:38
David Hall
30.2k1010 gold badges8484 silver badges119119 bronze badges
answered Oct 30 '08 at 1:45
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What is the 'new' keyword in JavaScript?
...n's external, accessible, prototype object (every function object automatically has a prototype property).
It makes the this variable point to the newly created object.
It executes the constructor function, using the newly created object whenever this is mentioned.
It returns the newly created objec...
Is it possible to specify your own distance function using scikit-learn K-Means Clustering?
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Here's a small kmeans that uses any of the 20-odd distances in
scipy.spatial.distance, or a user function.
Comments would be welcome (this has had only one user so far, not enough);
in particular, what are your N, dim, k, metric ?
#!/u...
Why does modern Perl avoid UTF-8 by default?
...?????????????????????
Set your PERL_UNICODE envariable to AS. This makes all Perl scripts decode @ARGV as UTF‑8 strings, and sets the encoding of all three of stdin, stdout, and stderr to UTF‑8. Both these are global effects, not lexical ones.
At the top of your source file (program, module, l...
How to validate an email address in JavaScript
...b"@gmail.com, _@gmail.com, 1@gmail.com , 1_example@something.gmail.com are all valid, but Gmail will never allow any of these email addresses. You should do this by accepting the email address and sending an email message to that email address, with a code/link the user must visit to confirm validit...
How do I count a JavaScript object's attributes? [duplicate]
...ry object in JavaScript derives from — includes many attributes automatically, and the exact set of attributes you get depends on the particular interpreter and what code has executed before yours. So, you somehow have to separate the ones you defined from those you got "for free."
Here's one way...