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Calling virtual functions inside constructors
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Calling virtual functions from a constructor or destructor is dangerous and should be avoided whenever possible. All C++ implementations should call the version of the function defined at the level of the hierarchy in the cur...
Creating a comma separated list from IList or IEnumerable
...;T> source)
{
return new List<T>(source).ToArray();
}
Then call it like this:
IEnumerable<string> strings = ...;
string[] array = Helpers.ToArray(strings);
You can then call string.Join. Of course, you don't have to use a helper method:
// C# 3 and .NET 3.5 way:
string joine...
Big O of JavaScript arrays
...pending - Amortized O(1) (sometimes resizing the hashtable is required; usually only insertion is required)
Prepending - O(n) via unshift, since it requires reassigning all the indexes
Insertion - Amortized O(1) if the value does not exist. O(n) if you want to shift existing values (Eg, using splice...
Redirect stderr and stdout in Bash
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@Daniel, but this question is specifically about bash
– John La Rooy
Aug 19 '13 at 3:38
3
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MySQL Error 1093 - Can't specify target table for update in FROM clause
... criteria. This will cause MySQL to see the table as two different things, allowing destructive changes to go ahead.
UPDATE tbl AS a
INNER JOIN tbl AS b ON ....
SET a.col = b.col
Alternatively, try nesting the subquery deeper into a from clause ...
If you absolutely need the subquery, there's a ...
Java switch statement multiple cases
...ure why a responder said it was not possible. This is fine, and I do this all the time:
switch (variable)
{
case 5:
case 6:
etc.
case 100:
doSomething();
break;
}
share
|
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How to escape special characters in building a JSON string?
...Tab
\" Double quote
\\ Backslash character
However, even if it is totally contrary to the spec, the author could use \'.
This is bad because :
It IS contrary to the specs
It is no-longer JSON valid string
But it works, as you want it or not.
For new readers, always use a double quote...
How to re-sync the Mysql DB if Master and slave have different database incase of Mysql replication?
...ck) issue the command to get a dump of the master:
mysqldump -u root -p --all-databases > /a/path/mysqldump.sql
Now you can release the lock, even if the dump hasn't ended yet. To do it, perform the following command in the MySQL client:
UNLOCK TABLES;
Now copy the dump file to the slave us...
In Python, how to display current time in readable format
...e.g., -0400. %Z gives you current timezone name (or abbreviation) automatically. Python doesn't support %l, you could use %I instead.
– jfs
Dec 14 '13 at 19:30
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Converting Mercurial folder to a Git repository
... naXanaXa
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