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Flatten an Array of Arrays in Swift
Is there a counterpart in Swift to flatten in Scala, Xtend, Groovy, Ruby and co?
14 Answers
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Testing Abstract Classes
...mean testing the interface, as abstract classes can have concrete methods, and this concrete methods can be tested.
It is not so uncommon, when writing some library code, to have certain base class that you expect to extend in your application layer. And if you want to make sure that library code ...
ASP.NET: This method cannot be called during the application's pre-start initialization stage
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Can you please expand on that a little? Where in the web.config? What do the keys do? I'm having trouble finding online documentation of those keys.
– Kennet Belenky
Jan 19 '11 at 19:54
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How default .equals and .hashCode will work for my classes?
...t's (generally speaking; if you inherit from a class that redefined equals and/or hashCode, then you'll use that implementation instead).
From the documentation:
equals
The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, f...
Python : List of dict, if exists increment a dict value, if not append a new dict
...en easier:
from collections import defaultdict # available in Python 2.5 and newer
urls_d = defaultdict(int)
for url in list_of_urls:
urls_d[url] += 1
If you access the defaultdict using a key, and the key is not already in the defaultdict, the key is automatically added with a default valu...
How to get a vertical geom_vline to an x-axis of class date?
Even though I found Hadley's post in the google group on POSIXct and geom_vline , I could not get it done. I have a time series from and would like to draw a vertical line for years 1998, 2005 and 2010 for example. I tried with ggplot and qplot syntax, but still I either see no vertical line ...
How do I remove the space between inline/inline-block elements?
Given this HTML and CSS:
40 Answers
40
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Java: What is the difference between and ?
I am unable to understand the following text... Does it mean that <clinit> is for empty constructors? Why is important to have two different versions?
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Unable to forward search Bash history similarly as with CTRL-r
...earch forward as well. From the bash info manual, "8.2.5 Searching for Commands in the History":
To search backward in the history for a particular string, type C-r.
Typing C-s searches forward through the history.
The problem with Ctrl-S however is that sometimes collides with XON/XOFF flow...
Difference between dispatch_async and dispatch_sync on serial queue?
...k is finished whereas dispatch_async return after it is added to the queue and may not finished.
for this code
dispatch_async(_serialQueue, ^{ printf("1"); });
printf("2");
dispatch_async(_serialQueue, ^{ printf("3"); });
printf("4");
It may print 2413 or 2143 or 1234 but 1 always before 3
for ...