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How to validate an email address in PHP
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The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function:
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
// invalid emailaddress
}
Additionally you can check whether the do...
How to map and remove nil values in Ruby
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Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your case, as the block evaluates to falsey, simp...
How to replace a string in multiple files in linux command line
....bak 's/foo/bar/g' *.xx moves all .xx files to the equivalent .xx.bak name and then generates the .xx files with the foo→bar substitution.
– Anaphory
Oct 4 '14 at 22:35
26
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Which is more preferable to use: lambda functions or nested functions ('def')?
...efs are just syntactic sugar for an assignment, so the result is the same, and they are a lot more flexible and readable.
lambdas can be used for use once, throw away functions which won't have a name.
However, this use case is very rare. You rarely need to pass around unnamed function objects.
T...
What are the differences between 'call-template' and 'apply-templates' in XSL?
...name="dosomething">.
<xsl:apply-templates> is a little different and in it is the real power of XSLT: It takes any number of XML nodes (whatever you define in the select attribute), iterates them (this is important: apply-templates works like a loop!) and finds matching templates for them:...
Responsive font size in CSS
... respond to the browser zoom/type size settings, such as if you press Ctrl and + together on the keyboard while in the browser.
Media Queries
You would have to look at using media queries to reduce the font-size at certain intervals where it starts breaking your design and creating scrollbars.
For e...
Heap vs Binary Search Tree (BST)
What is the difference between a heap and BST?
8 Answers
8
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Using CSS :before and :after pseudo-elements with inline CSS?
... an HTML email signature with inline CSS (i.e. CSS in style attributes), and I am curious as to whether it's possible to use the :before and :after pseudo-elements.
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Why do pthreads’ condition variable functions require a mutex?
...adcast to, one or more of the threads on the waiting list will be woken up and the mutex will be magically locked again for that thread.
You typically see the following operation with condition variables, illustrating how they work. The following example is a worker thread which is given work via a...
Why doesn't Objective-C support private methods?
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The answer is... well... simple. Simplicity and consistency, in fact.
Objective-C is purely dynamic at the moment of method dispatch. In particular, every method dispatch goes through the exact same dynamic method resolution point as every other method dispatch. At...