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Checking whether something is iterable
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The proper way to check for iterability is as follows:
function isIterable(obj) {
// checks for null and undefined
if (obj == null) {
return false;
}
return typeof obj[Symbol.iterator] === 'function';
}
Why this works (iterable protocol i...
Python != operation vs “is not”
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== is an equality test. It checks whether the right hand side and the left hand side are equal objects (according to their __eq__ or __cmp__ methods.)
is is an identity test. It checks whether the right hand side and the left hand side ar...
Is explicitly closing files important?
In Python, if you either open a file without calling close() , or close the file but not using try - finally or the " with " statement, is this a problem? Or does it suffice as a coding practice to rely on the Python garbage-collection to close all files? For example, if one does this:
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Is there an equivalent to background-size: cover and contain for image elements?
I have a site with many pages and different background pictures, and I display them from CSS like:
14 Answers
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Is there a destructor for Java?
...ed. Hence there is no direct equivalent of a destructor.
There is an inherited method called finalize, but this is called entirely at the discretion of the garbage collector. So for classes that need to explicitly tidy up, the convention is to define a close method and use finalize only for sanity ...
How do you print in Sublime Text 2
Sublime Text 2 seems like a great editor. I just started using it a week ago in eval mode and it doesn't seem to have any printing functionality. This seems preposterous to me, but I can't find it anywhere.
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How do I check if a number is a palindrome?
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This is one of the Project Euler problems. When I solved it in Haskell I did exactly what you suggest, convert the number to a String. It's then trivial to check that the string is a pallindrome. If it performs well enough, then why bother making it more complex? Being a pallind...
How to pass command line arguments to a rake task
...ons and dependencies need to be inside arrays:
namespace :thing do
desc "it does a thing"
task :work, [:option, :foo, :bar] do |task, args|
puts "work", args
end
task :another, [:option, :foo, :bar] do |task, args|
puts "another #{args}"
Rake::Task["thing:work"].invoke(args[:o...
Is there any downside for using a leading double slash to inherit the protocol in a URL? i.e. src=“/
I have a stylesheet that loads images from an external domain and I need it to load from https:// from secure order pages and http:// from other pages, based on the current URL. I found that starting the URL with a double slash inherits the current protocol. Do all browsers support this technique?...
I lose my data when the container exits
Despite Docker's Interactive tutorial and faq I lose my data when the container exits.
11 Answers
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