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Python's json module, converts int dictionary keys to strings
... which implement a __hash__ method. (The Lua docs suggest that it automatically uses the object's ID as a hash/key even for mutable objects and relies on string interning to ensure that equivalent strings map to the same objects).
In Perl, Javascript, awk and many other languages the keys for has...
Best way to create an empty map in Java
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You'll have to use the latter sometimes when the compiler cannot automatically figure out what kind of Map is needed (this is called type inference). For example, consider a method declared like this:
public void foobar(Map<String, String> map){ ... }
When passing the empty Map direc...
“unrecognized selector sent to instance” error in Objective-C
...I was getting the error because I forgot to put a colon after the selector callback, thus causing a calling sequence mismatch. With the colon, I can keep the sender argument.
– user1886876
May 20 '13 at 22:34
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Scroll Element into View with Selenium
...enium 1.x or 2.x to scroll the browser window so that a particular element identified by an XPath is in view of the browser? There is a focus method in Selenium, but it does not seem to physically scroll the view in FireFox. Does anyone have any suggestions on how to do this?
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Custom Drawable for ProgressBar/ProgressDialog
Reading the limited documentation that Google has provided, I get the feeling that it is possible to change the look (drawable) of a ProgressBar/ProgressDialog by simply creating a new style an assigning it to the style property of the ProgressBar. But I cannot get this to work properly. Here is wha...
HashMap with multiple values under the same key
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No, not just as a HashMap. You'd basically need a HashMap from a key to a collection of values.
If you're happy to use external libraries, Guava has exactly this concept in Multimap with implementations such as ArrayListMultimap and HashMultimap.
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Multiple types were found that match the controller named 'Home'
... often happens when you use areas and you have the same controller name inside the area and the root. For example you have the two:
~/Controllers/HomeController.cs
~/Areas/Admin/Controllers/HomeController.cs
In order to resolve this issue (as the error message suggests you), you could use namesp...
How to get the home directory in Python?
...re working with pathlib, you may prefer the pathlib solution (and omit the call of str). If you just want the path as string, they both do the same.
– Niklas Mertsch
Aug 15 '19 at 12:31
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How do you implement a private setter when using an interface?
...o not part of interface
Setter is not part of interface, so it cannot be called via your interface:
IBar bar = new Bar();
bar.Foo = 42; // will not work thus setter is not defined in interface
bar.Poop(); // will not work thus Poop is not defined in interface
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Index on multiple columns in Ruby on Rails
...columns in sequence starting at the beginning. i.e. if you index on [:user_id, :article_id], you can perform a fast query on user_id or user_id AND article_id, but NOT on article_id.
Your migration add_index line should look something like this:
add_index :user_views, [:user_id, :article_id]
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