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Creating instance of type without default constructor in C# using reflection
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I originally posted this answer here, but here is a reprint since this isn't the exact same question but has the same answer:
FormatterServices.GetUninitializedObject() will create an instance without calling a constructor. I found...
Concatenate two slices in Go
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Is this at all performant when the slices are quite big? Or does the compiler not really pass all the elements as parameters?
– Toad
Sep 24 '14 at 8:57
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printf with std::string?
...f what it expects definitely won't give you the results you want. It's actually undefined behaviour, so anything at all could happen.
The easiest way to fix this, since you're using C++, is printing it normally with std::cout, since std::string supports that through operator overloading:
std::cout...
Get keys from HashMap in Java
...HashMap contains more than one key. You can use keySet() to get the set of all keys.
team1.put("foo", 1);
team1.put("bar", 2);
will store 1 with key "foo" and 2 with key "bar". To iterate over all the keys:
for ( String key : team1.keySet() ) {
System.out.println( key );
}
will print "foo"...
Is “inline” without “static” or “extern” ever useful in C99?
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Actually this excellent answer also answers your question, I think:
What does extern inline do?
The idea is that "inline" can be used in a header file, and then "extern inline" in a .c file. "extern inline" is just how you ins...
How do I find where JDK is installed on my windows machine?
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Actually, the form %VAR_NAME% is Windows
– sblundy
Jan 13 '11 at 14:29
2
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pandas GroupBy columns with NaN (missing) values
...n the Missing Data section of the docs:
NA groups in GroupBy are automatically excluded. This behavior is consistent with R, for example.
One workaround is to use a placeholder before doing the groupby (e.g. -1):
In [11]: df.fillna(-1)
Out[11]:
a b
0 1 4
1 2 -1
2 3 6
In [12]: df.fil...
Using awk to print all columns from the nth to the last
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will print all but very first column:
awk '{$1=""; print $0}' somefile
will print all but two first columns:
awk '{$1=$2=""; print $0}' somefile
share
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SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?
... cross join produces a cartesian product between the two tables, returning all possible combinations of all rows. It has no on clause because you're just joining everything to everything.
A full outer join is a combination of a left outer and right outer join. It returns all rows in both tables t...
Best way to handle list.index(might-not-exist) in python?
...thonic solution is to use only try/except and not the -1 sentinel value at all. I.E. you should rewrite otherfunction. On the other hand, if it ain't broke, ...
– Andrew Jaffe
Jan 25 '10 at 15:49
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