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javascript set a variable if undefined
I know that I can test for a javascript variable and then define it if it is undefined, but is there not some way of saying
...
Which is the preferred way to concatenate a string in Python?
...ring to a string variable is to use + or +=. This is because it's readable and fast. They are also just as fast, which one you choose is a matter of taste, the latter one is the most common. Here are timings with the timeit module:
a = a + b:
0.11338996887207031
a += b:
0.11040496826171875
Howeve...
What are best practices for validating email addresses on iOS 2.0
...his modification of DHValidation:
- (BOOL) validateEmail: (NSString *) candidate {
NSString *emailRegex =
@"(?:[a-z0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[a-z0-9!#$%\\&'*+/=?\\^_`{|}"
@"~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\"
@"x7f]|\\\\[\\x01-\\x09\\x0b\\x0c...
PHP abstract properties
...s of data reserved in memory on initialization.
A function on the other hand can be declared (types, name, parameters) without being defined (function body missing) and thus, can be made abstract.
"Abstract" only indicates that something was declared but not defined and therefore before using it,...
Can I use git diff on untracked files?
...diff output, or is my best bet to use git add on the newly created files and the existing files I have edited, then use:
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Unittest setUp/tearDown for several tests
... is fired at the beginning/end of a scenario of tests? The functions setUp and tearDown are fired before/after every single test.
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How To Format A Block of Code Within a Presentation? [closed]
...lighter:
http://markup.su/highlighter/
or
http://hilite.me/
Just copy and paste into your document.
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raw_input function in Python
... the user (the optional arg of raw_input([arg])), gets input from the user and returns the data input by the user in a string. See the docs for raw_input().
Example:
name = raw_input("What is your name? ")
print "Hello, %s." % name
This differs from input() in that the latter tries to interpret...
Any good, visual HTML5 Editor or IDE? [closed]
... explicit support for node.js development, offers real-time collaboration, and you get bash into the deal with all its most popular tools (gcc included). All without having to open anything other than your browser.
I think that's Pretty Awesome.
EDIT Q3 2013 I would also suggest JetBrains WebStorm...
Why are margin/padding percentages in CSS always calculated against width?
... Since the
height of the child is dependent on the height of the parent, and the
height of the parent is dependent on the height of the child, we'll
either have inaccurate height, or an infinite loop. Sure, this only
affects the case where offset parent === parent, but still. It's an
odd c...