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Java ArrayList copy
...a reference) to l2. They will both refer to the same object.
Creating a shallow copy is pretty easy though:
List<Integer> newList = new ArrayList<>(oldList);
(Just as one example.)
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How to check if a variable is not null?
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This check is actually not safe. If myvar is 0, false or any other falsy value the test will fail (if you only intend to check for not null). So only use this to check for not null if the variable can never have another falsy value.
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Pipe subprocess standard output to a variable [duplicate]
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@Insomaniacal In this case, I knew usage is generally dumped to stderr. But in general, a simple test is to cmd > /dev/null if you still see output it's going to stderr. Confirm by piping stderr cmd 2> /dev/null and it should vanish into /dev/null.
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Creating a temporary directory in Windows?
... This seems a little dangerous. In particular, there's a chance (small, but non-zero, right?) that Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()) will return the name of a directory that already exists. Since Directory.CreateDirectory(tempDirectory) won't throw an exception if te...
WPF Auto height in code
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Perhaps this link will help you.
At times, you may want to
programmatically set the Height or
Width of a WPF element to Auto in
code. To do this, just use the
Double.NaN (Not a Number) value.
For example, in C#:
this.txtName.Width = Double.NaN;
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builtins.TypeError: must be str, not bytes
... couldn't because they were using stdio). Now it can annoy Python users on all platforms. Hopefully, it will be worth the pain.
– Brent Bradburn
Aug 17 '13 at 6:11
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How to listen for changes to a MongoDB collection?
...tricks. The key here is the oplog.
When you run MongoDB in a Replica Set, all of the MongoDB actions are logged to an operations log (known as the oplog). The oplog is basically just a running list of the modifications made to the data. Replicas Sets function by listening to changes on this oplog a...
javascript check for not null
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while technically this works, a double not (!!) is a programming faux-pas. It is really the equivalent of if(val), which is much clearer to read. I would stick to that (fyi Ujwal, !!val should technically work in C or C++ also) see here f...
What is the purpose of Order By 1 in SQL select statement?
...is only has the sql tag. In Standard SQL only column correlation names are allowed in the OREDER BY clause because, in theory, the table correlation names are out of scope i.e. should be ORDER BY PAYMENT_DATE;. Of course, not all SQL implementations conform to Standards.
– oned...
Can unit testing be successfully added into an existing production project? If so, how and is it wor
...oject that is in production. It was started 18 months ago before I could really see any benefit of TDD (face palm) , so now it's a rather large solution with a number of projects and I haven't the foggiest idea where to start in adding unit tests. What's making me consider this is that occasionally...