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How to check file MIME type with javascript before upload?
... that the file MIME type could be checked using javascript on client side. Now, I understand that the real validation still has to be done on server side. I want to perform a client side checking to avoid unnecessary wastage of server resource.
...
Named regular expression group “(?Pregexp)”: what does “P” stand for?
...Perl 5; O'Reilly
publishes books about both languages.)
As you may know, Python 1.5 adds a new regular expression module that
more closely matches Perl's syntax. We've tried to be as close to the
Perl syntax as possible within Python's syntax. However, the regex
syntax has some Python...
What is java interface equivalent in Ruby?
...ple: where in java.util.Set<E> does it actually say that it is, you know, a set? Nowhere! Or more precisely, in the documentation. In English.
In pretty much all cases of interfaces, both from Java and .NET, all the relevant information is actually in the docs, not in the types. So, if the typ...
Why wasn't PyPy included in standard Python?
...
It is worth noting that PyPy now comes with an incremental GC, and is potentially more suitable for games as a consequence.
– porgarmingduod
Oct 23 '13 at 11:55
...
What is the difference between \r and \n?
... to start printing on the next line.
Obviously that's somewhat irrelevant now, although depending on the console you may still be able to use \r to move to the start of the line and overwrite the existing text.
More importantly, Unix tends to use \n as a line separator; Windows tends to use \r\n a...
How do I replace NA values with zeros in an R dataframe?
...u post it and not worked. Because this I posted the question. But I tried know and worked perfectly. I think I was doing something wrong.
– Renato Dinhani
Nov 17 '11 at 14:08
12
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Using the scrollwheel in GNU screen
...
Yes, I know about scrollback mode. I was hoping that I would not have to manually enter scrollback mode in order to use the mouse. Thanks.
– JesperE
Jan 24 '09 at 20:34
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When to use an interface instead of an abstract class and vice versa?
...hod" is that it's nearly always somewhat re-entrant - the "derived" class knows about not just the "abstract" method of its base class that it is implementing, but also about the public methods of the base class, even though most times it does not need to call them.
(Overly simplified) example:
ab...
Why do we need a pure virtual destructor in C++?
...class Base
{
public:
Base();
virtual ~Base() = 0; // Pure virtual, now no one can create the Base Object directly
};
Base::Base() { cout << "Base Constructor" << endl; }
Base::~Base() { cout << "Base Destructor" << endl; }
class Derived : public Base
{
public:
...
“git rm --cached x” vs “git reset head -- x”?
... commit it, you add it to the tree as well.
It will probably help you to know the three more common flags in git reset:
git reset [--<mode>] [<commit>]
This form resets the current branch head to <commit> and possibly
updates the index (resetting it to the tree of <...