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Returning IEnumerable vs. IQueryable
...ecution.
The difference is that IQueryable<T> is the interface that allows LINQ-to-SQL (LINQ.-to-anything really) to work. So if you further refine your query on an IQueryable<T>, that query will be executed in the database, if possible.
For the IEnumerable<T> case, it will be L...
Python pip install fails: invalid command egg_info
I find that recently often when I try to install a Python package using pip , I get the error(s) below.
15 Answers
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Representing null in JSON
...s of type undefined.
JSON2 {"myCount": null}
In this case, myCount is actually defined, albeit its value is null. This is not the same as both "not undefined and not null", and if you were testing for one condition or the other, this might succeed whereas JSON1 would fail.
This is the definitive wa...
How does the “final” keyword in Java work? (I can still modify an object.)
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You are always allowed to initialize a final variable. The compiler makes sure that you can do it only once.
Note that calling methods on an object stored in a final variable has nothing to do with the semantics of final. In other words:...
How to convert a string to lower or upper case in Ruby
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You can find out all the methods available on a String by opening irb and running:
"MyString".methods.sort
And for a list of the methods available for strings in particular:
"MyString".own_methods.sort
I use this to find out new and int...
Is calculating an MD5 hash less CPU intensive than SHA family functions?
...s with sphlib, a library of hash function implementations in C (and Java). All implementations are from the same author (me) and were made with comparable efforts at optimizations; thus the speed differences can be considered as really intrinsic to the functions.
As a point of comparison, consider ...
Is Ruby pass by reference or by value?
...en I perform a save on the @user object I lose the errors that were initially stored in the lang_errors variable.
13 An...
Find kth smallest element in a binary search tree in Optimum way
I need to find the kth smallest element in the binary search tree without using any static/global variable. How to achieve it efficiently?
The solution that I have in my mind is doing the operation in O(n), the worst case since I am planning to do an inorder traversal of the entire tree. But deep do...
In what situations would AJAX long/short polling be preferred over HTML5 WebSockets?
I am building a small chat application for friends, but unsure about how to get information in a timely manner that is not as manual or as rudimentary as forcing a page refresh.
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Python dictionary: are keys() and values() always the same order?
...e always a 1-to-1 mapping (assuming the dictionary is not altered between calling the 2 methods).
8 Answers
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