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Most efficient way to increment a Map value in Java
...ood answers to this question--thanks folks--so I decided to run some tests and figure out which method is actually fastest. The five methods I tested are these:
the "ContainsKey" method that I presented in the question
the "TestForNull" method suggested by Aleksandar Dimitrov
the "AtomicLong" meth...
How to Sync iPhone Core Data with web server, and then push to other devices? [closed]
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I suggest carefully reading and implementing the sync strategy discussed by Dan Grover at iPhone 2009 conference, available here as a pdf document.
This is a viable solution and is not that difficult to implement (Dan implemented this in several of its...
Python csv string to array
Anyone know of a simple library or function to parse a csv encoded string and turn it into an array or dictionary?
10 Answe...
config.assets.compile=true in Rails production, why not?
...or a file in /assets is passed to Sprockets. On the first request for each and every asset it is compiled and cached in whatever Rails is using for cache (usually the filesystem).
On subsequent requests Sprockets receives the request and has to look up the fingerprinted filename, check that the fil...
Strange, unexpected behavior (disappearing/changing values) when using Hash default value, e.g. Hash
...ior applies to any default value that is subsequently mutated (e.g. hashes and strings), not just arrays.
TL;DR: Use Hash.new { |h, k| h[k] = [] } if you want the most idiomatic solution and don’t care why.
What doesn’t work
Why Hash.new([]) doesn’t work
Let’s look more in-depth at why...
String's Maximum length in Java - calling length() method
...ALUE, which is 2^31 - 1 (or approximately 2 billion.)
In terms of lengths and indexing of arrays, (such as char[], which is probably the way the internal data representation is implemented for Strings), Chapter 10: Arrays of The Java Language Specification, Java SE 7 Edition says the following:
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Automatic TOC in github-flavoured-markdown
...ed two options to generate a toc for github-flavored-markdown:
DocToc Command Line Tool (source) requires node.js
Installation:
npm install doctoc
Usage:
npx doctoc . to add table of contents to all markdown files in the current and all sub directories.
DocToc WebApp
If you want to try it on...
Prevent “overscrolling” of web page
...n is problematic for both devices that don't respect the html styling hack and for mobile web browsers which look at the full overflow of body disregarding the height to which html was set.
– runspired
Jul 7 '15 at 19:46
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What is the most efficient way to loop through dataframes with pandas? [duplicate]
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The newest versions of pandas now include a built-in function for iterating over rows.
for index, row in df.iterrows():
# do some logic here
Or, if you want it faster use itertuples()
But, unutbu's suggestion to use numpy functions to avoi...
CSS Image size, how to fill, not stretch?
I have an image, and I want to set it a specific width and height (in pixels)
15 Answers
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