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What do two question marks together mean in C#?
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It's the null coalescing operator, and quite like the ternary (immediate-if) operator. See also ?? Operator - MSDN.
FormsAuth = formsAuth ?? new FormsAuthenticationWrapper();
expands to:
FormsAuth = formsAuth != null ? formsAuth : new FormsAuthenticationWr...
SQL Server 2008 can't login with newly created user
I'm using using Windows Vista and I'm having trouble logging in with a newly created user.
4 Answers
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SQL update query using joins
... gm.ManufacturerID = mm.ManufacturerID
WHERE im.mf_item_number like 'STA%' AND
gm.manufacturerID = 34
To make it clear... The UPDATE clause can refer to an table alias specified in the FROM clause. So im in this case is valid
Generic example
UPDATE A
SET foo = B.bar
FROM TableA A
JOIN TableB ...
How to tell which version of a gem a rails app is using
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In Rails 3 and Rails 4, use bundle show
In Rails 2, rake gems will print out what gems, dependencies, and versions are installed, frozen, etc.
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How to check if a query string value is present via JavaScript?
...k they lead to cleaner code, since they help me avoid nested if statements and show exactly what is going on at a certain point in code. As for the stict cases, both the left hand and right hand sides will always be numbers, so what difference would switching to strict equality operators make?
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When to use .First and when to use .FirstOrDefault with LINQ?
I've searched around and haven't really found a clear answer as to when you'd want to use .First and when you'd want to use .FirstOrDefault with LINQ.
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Why is inserting in the middle of a linked list O(1)?
...r business logic that a new node needs to be added (or an old one deleted) and you do so. You may add 50 nodes in a single iteration and each of those nodes is just O(1) the time to unlink two adjacent nodes and insert your new one..
Edit: Man, you type a second paragraph and all of a sudden inste...
How can I find the last element in a List?
... IMHO this doesn't deserve to be the top answer, it reads terribly and leaves the chance for an error if count is zero. The CleanCode™ approach would be to use Last/LastOrDefault as mentioned below.
– chillitom
Dec 4 '13 at 18:04
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Clean code to printf size_t in C++ (or: Nearest equivalent of C99's %z in C++)
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Most compilers have their own specifier for size_t and ptrdiff_t arguments, Visual C++ for instance use %Iu and %Id respectively, I think that gcc will allow you to use %zu and %zd.
You could create a macro:
#if defined(_MSC_VER) || defined(__MINGW32__) //__MINGW32__ should...
How do I fix the indentation of an entire file in Vi?
In Vim, what is the command to correct the indentation of all the lines?
16 Answers
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