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Why do we need Abstract factory design pattern?
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All of these examples describe the Factory Method Pattern, because all of them return a single product interface. None of these is an Abstract Factory Pattern, because none of them produce a family of related product interfac...
Error handling in C code
... your library as painless as possible think about these additions:
store all possible error-states in one typedef'ed enum and use it in your lib. Don't just return ints or even worse, mix ints or different enumerations with return-codes.
provide a function that converts errors into something huma...
Why does ~True result in -2?
...00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins with 1):
11111110 → 00000001 → 00000010
↑ ...
How to make button look like a link?
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If you don't want all buttons to be styled as links, scope the style with something like button.link {...styles...} then <button class="link">Your button</button>. This also avoids using !important which is always a good idea.
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How to determine if binary tree is balanced?
... some fraction of the minimum path length, like a half or a quarter.
It really doesn't matter usually. The point of any tree-balancing algorithm is to ensure that you do not wind up in the situation where you have a million nodes on one side and three on the other. Donal's definition is fine in the...
`from … import` vs `import .` [duplicate]
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I just tried import urllib.request and it doesn't work at all (python 2.6.5 Ubuntu).
– tkone
Feb 24 '12 at 23:33
6
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How to revert multiple git commits?
...e git checkout -f A -- . Will not delete these, you will have to do it manually. I applied this strategy now, thanks Jakub
– oma
Mar 31 '11 at 14:56
18
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How to commit a change with both “message” and “description” from the command line? [duplicate]
I'm new to both git and GitHub. I managed to set up everything locally on my Mac, so that now I can push commits to GitHub via git (on the command line, not the Mac app).
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Difference between shadowing and overriding in C#?
...dow
public override int Bar() {return 1;} //override
}
then when you call this:
A clA = new A();
B clB = new B();
Console.WriteLine(clA.Foo()); // output 5
Console.WriteLine(clA.Bar()); // output 5
Console.WriteLine(clB.Foo()); // output 1
Console.WriteLine(clB.Bar()); // output 1
//now let'...
The way to check a HDFS directory's size?
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Prior to 0.20.203, and officially deprecated in 2.6.0:
hadoop fs -dus [directory]
Since 0.20.203 (dead link) 1.0.4 and still compatible through 2.6.0:
hdfs dfs -du [-s] [-h] URI [URI …]
You can also run hadoop fs -help for more info and specifics...