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What is a NullReferenceException, and how do I fix it?
... case:
string GetCategory(Book b)
{
if (b == null)
return "Unknown";
return b.Category;
}
Explicitly check for null from method calls and throw a custom exception.
You can also throw a custom exception, only to catch it in the calling code:
string GetCategory(string bookTitle)
{
...
Custom numeric format string to always display the sign
...
Thank you, Kamil - I missed that. I have now corrected the force sign format: +#;-#;+0 (instead of +#;-#)
– Edward
Aug 25 '15 at 14:16
...
Custom HTTP headers : naming conventions
...ng application protocols to support both names (E.g, x-gzip & gzip are now equivalent). So, the official recommendation is to just name them sensibly without the "X-" prefix.
Update 2: On June 2012, the deprecation of recommendation to use the "X-" prefix has become official as RFC 6648. Belo...
Why doesn't Dictionary have AddRange?
...nderlying implementation would bypass the code for duplicate checking.
So now, you have a flag that allows the AddRange to support both cases, but has an undocumented side effect (which is something that the Framework designers worked really hard to avoid).
Summary
As there is no clear, consisten...
How can I truncate a datetime in SQL Server?
...rect way (old):
dateadd(dd, datediff(dd,0, getDate()), 0)
This is older now, but it's still worth knowing because it can also easily adapt for other time points, like the first moment of the month, minute, hour, or year.
This correct way uses documented functions that are part of the ansi standa...
Where are Docker images stored on the host machine?
...ific storage for contents of the images.
/var/lib/docker/graph/<id> now only contains metadata about the image, in the json and layersize files.
In the case of aufs:
/var/lib/docker/aufs/diff/<id> has the file contents of the images.
/var/lib/docker/repositories-aufs is a JSON file ...
What's the @ in front of a string in C#?
... Oh my, that sounds annoying... even more glad I'm using C# now :p
– Svish
Feb 17 '09 at 11:15
You cann...
How to directly initialize a HashMap (in a literal way)?
...Map("key", "value").
For Java Version 9 or higher:
Yes, this is possible now. In Java 9 a couple of factory methods have been added that simplify the creation of maps :
// this works for up to 10 elements:
Map<String, String> test1 = Map.of(
"a", "b",
"c", "d"
);
// this works for ...
leiningen - how to add dependencies for local jars?
... you could see if there's anything over there which can solve your problem now / might solve it in the future, when feature sets mature?
Anyway, it is possible that Leiningen may not in fact have a good story ready yet for some complex scenarios. If you feel this may be true of your case (and I mea...
How to retrieve POST query parameters?
...
Things have changed once again starting Express 4.16.0, you can now use express.json() and express.urlencoded() just like in Express 3.0.
This was different starting Express 4.0 to 4.15:
$ npm install --save body-parser
and then:
var bodyParser = require('body-parser')
app.use( bodyP...