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What is the use of ObservableCollection in .net?
...es to the collection (add, move, remove) occur. It is used heavily in WPF and Silverlight but its use is not limited to there. Code can add event handlers to see when the collection has changed and then react through the event handler to do some additional processing. This may be changing a UI or...
What are the advantages of NumPy over regular Python lists?
... single-precision floats in the cells would fit in 4 MB. Access in reading and writing items is also faster with NumPy.
Maybe you don't care that much for just a million cells, but you definitely would for a billion cells -- neither approach would fit in a 32-bit architecture, but with 64-bit build...
When to use static vs instantiated classes
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This is quite an interesting question -- and answers might get interesting too ^^
The simplest way to consider things might be :
use an instanciated class where each object has data on its own (like a user has a name)
use a static class when it's just a tool that...
Working with time DURATION, not time of day
I'm doing some benchmarking, and I want to use Excel to produce graphs of the results. I've got a simple but annoying problem which is baking my noodle.
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How to handle a lost KeyStore password in Android?
I have forgotten my Keystore password and I don't really know what to do anymore (I can't or won't give any excuses for it). I want to update my app because I just fixed a bug but it's not possible anymore. What happens if I use the same Keystore but create a new key? Would I still be able to update...
stopPropagation vs. stopImmediatePropagation
What's the difference between event.stopPropagation() and event.stopImmediatePropagation() ?
9 Answers
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What is a sealed trait?
...only extended in a single file, the compiler knows every possible subtypes and can reason about it.
For instance with the declaration:
sealed trait Answer
case object Yes extends Answer
case object No extends Answer
The compiler will emit a warning if a match is not exhaustive:
scala> val x:...
How to extract text from a PDF? [closed]
Can anyone recommend a library/API for extracting the text and images from a PDF?
We need to be able to get at text that is contained in pre-known regions of the document, so the API will need to give us positional information of each element on the page.
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Using arrays or std::vectors in C++, what's the performance gap?
...hould be avoided. There is the problem you have to keep track of the size, and you need to delete them manually and do all sort of housekeeping.
Using arrays on the stack is also discouraged because you don't have range checking, and passing the array around will lose any information about its siz...
Parse string to DateTime in C#
I have date and time in a string formatted like that one:
8 Answers
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