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How do I check in JavaScript if a value exists at a certain array index?
... element with index i is defined to be part of the array if i is between 0 and array.length - 1 inclusive. If i is not in this range it's not in the array.
So by concept, arrays are linear, starting with zero and going to a maximum, without any mechanism for having "gaps" inside that range where n...
How to load/edit/run/save text files (.py) into an IPython notebook cell?
... individual cells of an open IPython notebook so that they can edited, run and then saved. Can this be done?
4 Answers
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Declaring variables inside loops, good practice or bad practice?
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The compiler knows that the variable scope is limited to inside the loop, and therefore will issue a proper error message if the variable is by mistake referenced elsewhere.
Last but not least, some dedicated optimization can be performed more efficiently by the compiler (most importantly register ...
Efficient way to return a std::vector in c++
How much data is copied, when returning a std::vector in a function and how big an optimization will it be to place the std::vector in free-store (on the heap) and return a pointer instead i.e. is:
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What is the ideal data type to use when storing latitude / longitude in a MySQL database?
... MYSQL Spatial is a good option, but still has significant limits and caveats (as of 6). Please see my answer below...
– James Schek
Oct 2 '08 at 15:43
1
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Java 8: performance of Streams vs Collections
... the middle of the list using iterator.
Stop writing benchmarking code by hand, use JMH.
Proper benchmarks:
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@BenchmarkMode(Mode.AverageTime)
@OperationsPerInvocation(StreamVsVanilla.N)
public class StreamVsVanilla {
public static final int N = 10000;
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How to update a record using sequelize for node?
I'm creating a RESTful API with NodeJS, express, express-resource, and Sequelize that is used to manage datasets stored in a MySQL database.
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Why is transposing a matrix of 512x512 much slower than transposing a matrix of 513x513?
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The explanation comes from Agner Fog in Optimizing software in C++ and it reduces to how data is accessed and stored in the cache.
For terms and detailed info, see the wiki entry on caching, I'm gonna narrow it down here.
A cache is organized in sets and lines. At a time, only one set is u...
When should the xlsm or xlsb formats be used?
... (in particular, .xlsx , .xlsm , .xlsb ). I've got no problem to understand the use and purpose of .xlsx format but I am still wondering whether we should use a .xlsm or a .xlsb format when creating a file containing some VBA.
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NHibernate ISession Flush: Where and when to use it, and why?
...nfused is the use of session.Flush ,in conjunction with session.Commit , and session.Close .
4 Answers
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