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Most efficient method to groupby on an array of objects
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Here is one that outputs array and not object: groupByArray(xs, key) { return xs.reduce(function (rv, x) { let v = key instanceof Function ? key(x) : x[key]; let el = rv.find((r) => r && r.key === v); ...
Android 4.3 Bluetooth Low Energy unstable
...sting on the Nexus 4). After getting started with the official BLE APIs in Android 4.3, I have noticed that after I connect a device for the first time I am rarely able to successfully connect to / communicate with that device or any other device again.
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Vagrant error: NFS is reporting that your exports file is invalid
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Try using the known good versions of VirtualBox and Vagrant noted in Discourse as Your First Rails App:
Vagrant 1.1.2
VirtualBox 4.2.10
I was having the same issue on Mac (OS X 10.9 (Mavericks)), but rolling back to these versions seemed to fix it for me.
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How to limit the amount of concurrent async I/O operations?
...can create delegate-bound tasks on the TPL that have not yet been started, and allow for a custom task scheduler to limit the concurrency. In fact, there's an MSDN sample for it here:
See also TaskScheduler .
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Improving bulk insert performance in Entity framework [duplicate]
I want to insert 20000 records in a table by entity framework and it takes about 2 min. Is there any way other than using SP to improve its performance. This is my code:
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How can we programmatically detect which iOS version is device running on? [duplicate]
I want to check if the user is running the app on iOS less than 5.0 and display a label in the app.
10 Answers
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Get Android Phone Model programmatically
... to know if there is a way for reading the Phone Model programmatically in Android.
16 Answers
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How to use '-prune' option of 'find' in sh?
I don't quite understand the example given from the man find , can anyone give me some examples and explanations? Can I combine regular expression in it?
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What is null in Java?
...ceof operator is true if the value of the RelationalExpression is not null and the reference could be cast to the ReferenceType without raising a ClassCastException. Otherwise the result is false.
This means that for any type E and R, for any E o, where o == null, o instanceof R is always false.
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What is the difference between an int and a long in C++?
... (an answer by example) with some of the details below regarding the C++ standard. The draft for C++0x is at open-std.org/JTC1/SC22/WG21/docs/papers/2008/n2798.pdf and it is marked up so you can see the differences between it and the last rev.
– Patrick Johnmeyer
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