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What does the Q_OBJECT macro do? Why do all Qt objects need this macro?
I just started using Qt and noticed that all the example class definitions have the macro Q_OBJECT as the first line. What is the purpose of this preprocessor macro?
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In Ruby, is there an Array method that combines 'select' and 'map'?
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I usually use map and compact together along with my selection criteria as a postfix if. compact gets rid of the nils.
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}
=> [3, 3, 3, nil, nil, nil]
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}.compact
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how to stop Javascript forEach? [duplicate]
I'm playing with Node.js and Mongoose — trying to find specific comment in deep comments nesting with recursive function and forEach within. Is there a way to stop Node.js forEach ? As I understand every forEach iteration is a function and and I can't just do break , only return but this w...
How to parse a string to an int in C++?
...at: stoi, stol, stoll, stoul and so on.
int myNr = std::stoi(myString);
It will throw an exception on conversion error.
Even these new functions still have the same issue as noted by Dan: they will happily convert the string "11x" to integer "11".
See more: http://en.cppreference.com/w/cpp/stri...
Why 0 is true but false is 1 in the shell?
The above will output 1 , which is contradictory with all other programming languages I know.
10 Answers
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In .NET, which loop runs faster, 'for' or 'foreach'?
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Patrick Smacchia blogged about this last month, with the following conclusions:
for loops on List are a bit more than 2 times cheaper than foreach
loops on List.
Looping on array is around 2 times cheaper than looping on List.
As a consequence, looping on array...
Identity increment is jumping in SQL Server database
... of my tables Fee in column "ReceiptNo" in SQL Server 2012 database identity increment suddenly started jumping to 100s instead of 1 depending on the following two things.
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What resources are shared between threads?
...follow
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edited Mar 28 '19 at 9:44
Hearen
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Java's L number (long) specification
It appears that when you type in a number in Java, the compiler automatically reads it as an integer, which is why when you type in (long) 6000000000 (not in integer's range) it will complain that 6000000000 is not an integer. To correct this, I had to specify 6000000000L . I just learned abo...
What is trunk, branch and tag in Subversion? [duplicate]
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The trunk is the main line of development in a SVN repository.
A branch is a side-line of development created to make larger, experimental or disrupting work without annoying users of the trunk version. Also, branches can be used to create development lines for multiple versions ...