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When is it better to use an NSSet over an NSArray?
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When the order of the items in the collection is not important, sets offer better performance for finding items in the collection.
The reason is that a set uses hash values to find items (like a dictionary) while an array has to iterate over its ...
A command-line HTML pretty-printer: Making messy HTML readable [closed]
...Tidy Project: http://www.html-tidy.org/
The granddaddy of HTML tools, with support for modern standards.
There used to be a fork called tidy-html5 which since became the official thing. Here is its GitHub repository.
Tidy is a console application for Mac OS X, Linux, Windows, UNIX, and mor...
Why would a static nested interface be used in Java?
...dundant (a nested interface is automatically "static") and can be removed with no effect on semantics; I would recommend it be removed. The same goes for "public" on interface methods and "public final" on interface fields - the modifiers are redundant and just add clutter to the source code.
Eithe...
Javascript when to use prototypes
I'd like to understand when it is appropriate to use prototype methods in js. Should they always be used? Or are there cases where using them is not preferred and/or incurs a performance penalty?
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How to configure Mac OS X term so that git has color? [closed]
I've seen a Mac OS X git demo online in which it's configured to have multiple colors.
6 Answers
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Is a Java hashmap search really O(1)?
...o? Unless these hashmaps are vastly different from any of the hashing algorithms I was bought up on, there must always exist a dataset that contains collisions.
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must appear in the GROUP BY clause or be used in an aggregate function
... this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SELECT m.cname, m.wmname, t.mx
FROM (
SELECT cname, MAX(avg) AS mx
FROM makerar
GROUP BY cname
) t JOIN makerar m ON m.cname = t.cname AND t.mx...
Creating an empty list in Python
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Here is how you can test which piece of code is faster:
% python -mtimeit "l=[]"
10000000 loops, best of 3: 0.0711 usec per loop
% python -mtimeit "l=list()"
1000000 loops, best of 3: 0.297 usec per loop
However, in practice, this initialization is most likely an extremely small part of you...
Java: when to use static methods
I am wondering when to use static methods? Say if I have a class with a few getters and setters, a method or two, and I want those methods only to be invokable on an instance object of the class. Does this mean I should use a static method?
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Various ways to remove local Git changes
I just cloned a git repository and checked out a branch. I worked on it, and then decided to remove all my local changes, as I wanted the original copy.
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