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What does the ??!??! operator do in C?
...?! is a trigraph that translates to |. So it says:
!ErrorHasOccured() || HandleError();
which, due to short circuiting, is equivalent to:
if (ErrorHasOccured())
HandleError();
Guru of the Week (deals with C++ but relevant here), where I picked this up.
Possible origin of trigraphs or as @...
Select first 4 rows of a data.frame in R
...row.index, column.index]
Read help(`[`) for more detail on this subject, and also read about index matrices in the Introduction to R.
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Retrieving Property name from lambda expression
...r 23 '09 at 4:14
Cameron MacFarlandCameron MacFarland
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PostgreSQL: insert from another table
I'm trying to insert data to a table from another table and the tables have only one column in common. The problem is, that the TABLE1 has columns that won't accept null values so I can't leave them empty and I can't get them from the TABLE2.
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How would you make a comma-separated string from a list of strings?
... you map, for instance, ['a', 'b', 'c'] to 'a,b,c' ? (The cases ['s'] and [] should be mapped to 's' and '' , respectively.)
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Likelihood of collision using most significant bits of a UUID in Java
If I'm using Long uuid = UUID.randomUUID().getMostSignificantBits() how likely is it to get a collision. It cuts off the least significant bits, so there is a possibility that you run into a collision, right?
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Determining if an Object is of primitive type
I have an Object[] array, and I am trying to find the ones that are primitives. I've tried to use Class.isPrimitive() , but it seems I'm doing something wrong:
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Draw multi-line text to Canvas
...es... I'd like to write multi-line text to a custom View via a Canvas , and in onDraw() I have:
16 Answers
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How to install plugin for Eclipse from .zip
...ll Eclipse plugin from .zip? I have installed plugins by choosing the site and then check but never from .zip. Can anybody help?
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Is there any Rails function to check if a partial exists?
...et an Exception. I'd like to check if a partial exists before rendering it and in case it doesn't exist, I'll render something else. I did the following code in my .erb file, but I think there should be a better way to do this:
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