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List comprehension in Ruby
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I made a quick benchmark comparing the three alternatives and map-compact really seems to be the best option.
Performance test (Rails)
require 'test_helper'
require 'performance_test_help'
class ListComprehensionTest < ActionController::PerformanceTest
TEST_ARRA...
Android Reading from an Input stream efficiently
...can now use total without converting it to String, but if you need the result as a String, simply add:
String result = total.toString();
I'll try to explain it better...
a += b (or a = a + b), where a and b are Strings, copies the contents of both a and b to a new object (note that you are also ...
do { … } while (0) — what is it good for? [duplicate]
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It's the only construct in C that you can use to #define a multistatement operation, put a semicolon after, and still use within an if statement. An example might help:
#define FOO(x) foo(x); bar(x)
if (condition)
FOO(x);
else // syntax error here
...;
Even using braces doe...
How to process SIGTERM signal gracefully?
...Mausy5043 Python allows you to not have parenthesis for defining classes. Although it's perfectly fine for python 3.x, but for python 2.x, best practice is to use "class XYZ(object):". Reason being: docs.python.org/2/reference/datamodel.html#newstyle
– Mayank Jaiswal
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C# 4.0: Can I use a TimeSpan as an optional parameter with a default value?
...'t simply execute TimeSpan.FromSeconds(2.0) and stick the bytes of the result into your compiled code.
As an example, consider if you tried to use DateTime.Now instead. The value of DateTime.Now changes every time it's executed. Or suppose that TimeSpan.FromSeconds took into account gravity. It's a...
Flask SQLAlchemy query, specify column names
...lumn that I want in my query using a model (it selects all columns by default)? I know how to do this with the sqlalchmey session: session.query(self.col1) , but how do I do it with with models? I can't do SomeModel.query() . Is there a way?
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Regex to match a digit two or four times
...syntax for that, but there are lots of ways to do it:
(?:\d{4}|\d{2}) <-- alternation: four digits or two
\d{2}(?:\d{2})? <-- two digits, and optionally two more
(?:\d{2}){1,2} <-- two digits, times one or two
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What are all the different ways to create an object in Java?
...s.forName()
If we know the name of the class & if it has a public default constructor we can create an object in this way.
MyObject object = (MyObject) Class.forName("subin.rnd.MyObject").newInstance();
C. Using clone()
The clone() can be used to create a copy of an existing object.
MyObject...
How do I delete/remove a shell function?
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unhash
unalias
unlimit
unsetopt
When in doubt with such things, type un<tab> to see the complete list.
(Slightly related: It's also nice to have functions/aliases like realiases, refunctions, resetopts, reenv, etc to "re-source" respective files, if you've separated/grouped them as such.)
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Convert interface{} to int
...u want a type assertion:
iAreaId := val.(int)
iAreaId, ok := val.(int) // Alt. non panicking version
The reason why you cannot convert an interface typed value are these rules in the referenced specs parts:
Conversions are expressions of the form T(x) where T is a type and x is an expression that...