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Passing a String by Reference in Java?
...] += "foo"; }
From a performance point of view, the StringBuilder is usually the best option.
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Writing a compiler in its own language
... compiler for language Foo cannot itself be written in Foo. More specifically, the first compiler for language Foo cannot be written in Foo, but any subsequent compiler could be written for Foo .
...
How to turn off INFO logging in Spark?
I installed Spark using the AWS EC2 guide and I can launch the program fine using the bin/pyspark script to get to the spark prompt and can also do the Quick Start quide successfully.
...
Try-finally block prevents StackOverflowError
...(2^N) where N is the maximum stack depth.
Imagine the maximum depth is 5
foo() calls
foo() calls
foo() calls
foo() calls
foo() which fails to call foo()
finally calls
foo() which fails to call foo()
finally
foo() calls
...
In C++, what is a virtual base class?
..." diagram is confusing, although it seems to be commonly used. This is actually a diagram showing class inheritance relationships -- not an object layout. The confusing part is that if we do use virtual, then the object layout looks like the diamond; and if we do not use virtual then the object la...
How to get the current branch name in Git?
...
git branch
should show all the local branches of your repo. The starred branch is your current branch.
If you want to retrieve only the name of the branch you are on, you can do:
git rev-parse --abbrev-ref HEAD
or with Git 2.22 and above:
git bran...
Using GCC to produce readable assembly?
...is nice:
-r shows symbol names on relocations (so you'd see puts in the call instruction below)
-R shows dynamic-linking relocations / symbol names (useful on shared libraries)
-C demangles C++ symbol names
-w is "wide" mode: it doesn't line-wrap the machine-code bytes
-Mintel: use GAS/binutils MA...
What does the exclamation mark do before the function?
...s just a function declaration. You would need an invocation, foo(), to actually run the function.
Now, when we add the seemingly innocuous exclamation mark: !function foo() {} it turns it into an expression. It is now a function expression.
The ! alone doesn't invoke the function, of course, but w...
Catching an exception while using a Python 'with' statement
... print 'oops'
If you want different handling for errors from the open call vs the working code you could do:
try:
f = open('foo.txt')
except IOError:
print('error')
else:
with f:
print f.readlines()
...
Can virtual functions have default parameters?
... or a derived class' -- is determined by the static type used to make the call to the function. If you call through a base class object, pointer or reference, the default denoted in the base class is used. Conversely, if you call through a derived class object, pointer or reference the defaults de...