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dplyr: “Error in n(): function should not be called directly”
...ction" specification, like example below:
delay <- dplyr::summarise(by_tailnum,
count = n(),
dist = mean(distance, na.rm = TRUE),
delay = mean(arr_delay, na.rm = TRUE))
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Enum type constraints in C# [duplicate]
What is the reason behind C# not allowing type constraints on Enum 's? I'm sure there is a method behind the madness, but I'd like to understand why it's not possible.
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Virtual member call in a constructor
I'm getting a warning from ReSharper about a call to a virtual member from my objects constructor.
18 Answers
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How to prevent form resubmission when page is refreshed (F5 / CTRL+R)
... It seems to me that if you redirect to the same page, then $_POST is cleared. As I understand it, that was the desired effect. That was MY desired effect, anyway. I think the answer would be better if it made that explicit, though.
– donutguy640
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linq where list contains any in list
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Sounds like you want:
var movies = _db.Movies.Where(p => p.Genres.Intersect(listOfGenres).Any());
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Tomcat: How to find out running tomcat version
....in/blog/check-jsp-tomcat-version
Save this code into a file called tomcat_version.jsp:
Tomcat Version : <%= application.getServerInfo() %><br>
Servlet Specification Version :
<%= application.getMajorVersion() %>.<%= application.getMinorVersion() %> <br> ...
How to change a table name using an SQL query?
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Use sp_rename:
EXEC sp_rename 'Stu_Table', 'Stu_Table_10'
You can find documentation on this procedure on MSDN.
If you need to include a schema name, this can only be included in the first parameter (that is, this cannot be use...
Hash and salt passwords in C#
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Actually this is kind of strange, with the string conversions - which the membership provider does to put them into config files. Hashes and salts are binary blobs, you don't need to convert them to strings unless you want to put...
NSDictionary - Need to check whether dictionary contains key-value pair or not
...uldn't we mistakenly think that the key isn't present in the dictionary at all?
– jbx72487
Feb 1 '13 at 18:51
13
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Finding the type of an object in C++
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dynamic_cast should do the trick
TYPE& dynamic_cast<TYPE&> (object);
TYPE* dynamic_cast<TYPE*> (object);
The dynamic_cast keyword casts a datum from one pointer or reference type to another, performing a runtime...