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Rails check if yield :area is defined in content_for
...content_for_whatever is deprecated.
Use content_for? instead, like this:
<% if content_for?(:whatever) %>
<div><%= yield(:whatever) %></div>
<% end %>
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impro...
Get the Highlighted/Selected text
...re interested in an implementation that will also deal with selections in <textarea> and texty <input> elements, you could use the following. Since it's now 2016 I'm omitting the code required for IE <= 8 support but I've posted stuff for that in many places on SO.
function getSe...
Get nth character of a string in Swift programming language
...r { self[index(startIndex, offsetBy: offset)] }
subscript(range: Range<Int>) -> SubSequence {
let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
return self[startIndex..<index(startIndex, offsetBy: range.count)]
}
subscript(range: ClosedRange&...
Android: Scale a Drawable or background image?
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To customize background image scaling create a resource like this:
<?xml version="1.0" encoding="utf-8"?>
<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
android:gravity="center"
android:src="@drawable/list_bkgnd" />
Then it will be centered in the vie...
:: (double colon) operator in Java 8
... a method itself to be passed as an argument (you can only pass method results, but never method references), the :: syntax was introduced in Java 8 to reference methods:
reduce(Math::max);
Note that this will be interpreted by the compiler, not by the JVM at runtime! Although it produces differe...
What is the difference between dict.items() and dict.iteritems() in Python2?
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It's part of an evolution.
Originally, Python items() built a real list of tuples and returned that. That could potentially take a lot of extra memory.
Then, generators were introduced to the language in general, and that method was reimplemented as an iterator-generator method n...
Monad in plain English? (For the OOP programmer with no FP background)
...and turn it into a more special type. For example, in C# consider Nullable<T>. This is an amplifier of types. It lets you take a type, say int, and add a new capability to that type, namely, that now it can be null when it couldn't before.
As a second example, consider IEnumerable<T>. I...
Why must jUnit's fixtureSetup be static?
...tance variables - the rest would have the instance variables at their default values - and the @Test method would be randomly selected, because the order of methods in the .class file is unspecified/compiler-dependent (IIRC, Java's reflection API returns the methods in the same order as they are dec...
What is the point of the diamond operator () in Java 7?
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The issue with
List<String> list = new LinkedList();
is that on the left hand side, you are using the generic type List<String> where on the right side you are using the raw type LinkedList. Raw types in Java effectively only exist...
AsyncTask and error handling on Android
...latter is great at what it does - asynchronous updates and handling of results in the main UI thread. What's unclear to me is how to handle exceptions if something goes haywire in AsyncTask#doInBackground .
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