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Checking for NULL pointer in C/C++ [closed]
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206
In my experience, tests of the form if (ptr) or if (!ptr) are preferred. They do not depend on ...
Difference between map and collect in Ruby?
...well: In C++'s Standard Template Library, it is called transform, in C# (3.0)'s LINQ library, it is provided as an extension method called Select. Map is also a frequently used operation in high level languages such as Perl, Python and Ruby; the operation is called map in all three of these language...
String concatenation vs. string substitution in Python
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... return "%s%s/%d" % (DOMAIN, QUESTIONS, n)
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>>> so_q_sub(1000)
'http://stackoverflow.com/questions/1000'
>>> def so_q_cat(n):
... return DOMAIN + QUESTIONS + '/' + str(n)
...
>>> so_q_cat(1000)
'http://stackoverflow.com/questions/1000'
>>> t1 = timeit.Tim...
How to escape braces (curly brackets) in a format string in .NET
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10 Answers
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Gem::LoadError for mysql2 gem, but it's already in Gemfile
... with rails 4.1.5) try using this version of mysql2:
gem 'mysql2', '~> 0.3.18'
Apparently mysql2 isn't still compatible with newer version of rails because rails 4.2.4 is pretty new as the time of answering this question by me 8 September 2015 so use the above line in your Gem file and run:
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How do I scale a stubborn SVG embedded with the tag?
...dd the following attributes:
preserveAspectRatio="xMinYMin meet"
viewBox="0 0 {width} {height}"
Replace {width} and {height} with some defaults for the viewBox. I used the values from the "width" and "height" attributes of the SVG tag and it seemed to work.
Save the SVG and it should now scale a...
Why do some C# lambda expressions compile to static methods?
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Action<string> withClosure = s => Console.WriteLine("My name is {0} and I am {1} years old", s, age);
Action<string> withoutClosure = s => Console.WriteLine("My name is {0}", s);
Console.WriteLine(withClosure.Method.IsStatic);
Console.WriteLine(withoutClosure.Method.IsStatic);
T...
Remove padding from columns in Bootstrap 3
...out the margins/paddings for each child column.
.nopadding {
padding: 0 !important;
margin: 0 !important;
}
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python pandas: apply a function with arguments to a series
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170
Newer versions of pandas do allow you to pass extra arguments (see the new documentation). So no...
?: operator (the 'Elvis operator') in PHP
...will leave foo unchanged.
Some more examples:
<?php
var_dump(5 ?: 0); // 5
var_dump(false ?: 0); // 0
var_dump(null ?: 'foo'); // 'foo'
var_dump(true ?: 123); // true
var_dump('rock' ?: 'roll'); // 'rock'
?>
By the way, it's called the Elvis operator.
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