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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...ison to data.frame.
Btw, if you tracemem(DT) then DT[2,b:=600] you'll see one copy reported. That is a copy of the first 10 rows that the print method does. When wrapped with invisible() or when called within a function or script, the print method isn't called.
All this applies inside functions t...
How do I forward declare an inner class? [duplicate]
...You can only forward declare it within the container.
You'll need to do one of the following
Make the class non-nested
Change your declaration order so that the nested class is fully defined first
Create a common base class that can be both used in the function and implemented by the nested cl...
JUnit Testing Exceptions [duplicate]
...(from here)
@Rule
public ExpectedException exception = ExpectedException.none();
@Test
public void testRodneCisloRok(){
exception.expect(IllegalArgumentException.class);
exception.expectMessage("error1");
new RodneCislo("891415",dopocitej("891415"));
}
and for older junit, this:
@Te...
What is the fastest integer division supporting division by zero no matter what the result is?
...test`; echo "Iterations $it, check $ch: exit status $?, output $time"; }; done; done
shows output that can be summarised in a table:
Iterations → | 0 | 1 | 2 | 3 | 4 | 5
-------------+-------------------------------------------------------------------
Zeroes...
Remove a prefix from a string [duplicate]
...tarts with the prefix
text = text.replace(prefix, "", 1) # remove one instance of prefix
return text
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How do you validate a URL with a regular expression in Python?
...
A regex alone might be too much work, but for virtually every use-case, the use of urlparse needs to be augmented with regexes to validate a netloc (or other part) against a particular standard.
– Jonathan Vanasco...
Why does pthread_cond_wait have spurious wakeups?
... among the "core threadies" in
the working group, though I don't think anyone really disagreed with the intent
once they understood what it meant.
We followed that intent with several levels of justification. The first was that
"religiously" using a loop protects the application against its own...
Remove multiple spaces and new lines inside of String
... The simplest and the most elegant solution. Thanks. But there's one thing, this method is defined in Rails, so it'll work only in Rails applications, luckily that's my case.
– Kreeki
Aug 18 '11 at 12:05
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The split() method in Java does not work on a dot (.) [duplicate]
I have prepared a simple code snippet in order to separate the erroneous portion from my web application.
7 Answers
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How do I remove a key from a JavaScript object? [duplicate]
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Does anyone know the runtime of this operation?
– AjaxLeung
May 31 '16 at 18:31
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