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What does “var FOO = FOO || {}” (assign a variable or an empty object to that variable) mean in Java
Looking at an online source code I came across this at the top of several source files.
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How to delete a row by reference in data.table?
My question is related to assignment by reference versus copying in data.table . I want to know if one can delete rows by reference, similar to
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Showing the stack trace from a running Python application
I have this Python application that gets stuck from time to time and I can't find out where.
28 Answers
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how to exclude null values in array_agg like in string_agg using postgres?
If I use array_agg to collect names, I get my names separated by commas, but in case there is a null value, that null is also taken as a name in the aggregate. For example :
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With MySQL, how can I generate a column containing the record index in a table?
Is there any way I can get the actual row number from a query?
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C++ new int[0] — will it allocate memory?
A simple test app:
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How to remove the lines which appear on file B from another file A?
I have a large file A (consisting of emails), one line for each mail. I also have another file B that contains another set of mails.
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Are list-comprehensions and functional functions faster than “for loops”?
In terms of performance in Python, is a list-comprehension, or functions like map() , filter() and reduce() faster than a for loop? Why, technically, they run in a C speed , while the for loop runs in the python virtual machine speed ?.
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Filling a DataSet or DataTable from a LINQ query result set
How do you expose a LINQ query as an ASMX web service? Usually, from the business tier, I can return a typed DataSet or DataTable which can be serialized for transport over ASMX.
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How should I unit test threaded code?
I have thus far avoided the nightmare that is testing multi-threaded code since it just seems like too much of a minefield. I'd like to ask how people have gone about testing code that relies on threads for successful execution, or just how people have gone about testing those kinds of issues that ...