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.toArray(new MyClass[0]) or .toArray(new MyClass[myList.size()])?
Assuming I have an ArrayList
9 Answers
9
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Why are only final variables accessible in anonymous class?
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As noted in comments, some of this becomes irrelevant in Java 8, where final can be implicit. Only an effectively final variable can be used in an anonymous inner class or lambda expression though.
It's basically due to the way Java manages closures....
How did I get a value larger than 8 bits in size from an 8-bit integer?
I tracked down an extremely nasty bug hiding behind this little gem. I am aware that per the C++ spec, signed overflows are undefined behavior, but only when the overflow occurs when the value is extended to bit-width sizeof(int) . As I understand it, incrementing a char shouldn't ever be undefin...
What is the python keyword “with” used for? [duplicate]
What is the python keyword "with" used for?
2 Answers
2
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Dual emission of constructor symbols
...e improved in the future.
This newsgroup posting describes a problem with setting breakpoints in constructors due to this dual-emission. It's stated again that the root of the issue is support for polymorphism.
In fact, this is listed as a GCC "known issue":
G++ emits two copies of constructors ...
namedtuple and default values for optional keyword arguments
...>> Node()
Node(val=None, left=None, right=None)
Before Python 3.7
Set Node.__new__.__defaults__ to the default values.
>>> from collections import namedtuple
>>> Node = namedtuple('Node', 'val left right')
>>> Node.__new__.__defaults__ = (None,) * len(Node._field...
Why is 128==128 false but 127==127 is true when comparing Integer wrappers in Java?
...it to a Integer (capital I) the compiler emits:
Integer b2 =Integer.valueOf(127)
This line of code is also generated when you use autoboxing.
valueOf is implemented such that certain numbers are "pooled", and it returns the same instance for values smaller than 128.
From the java 1.6 source cod...
指定组件的大小 · App Inventor 2 中文网
...reen component behaves like a VerticalArrangement whose Height property is set to Automatic. When the Scrollable property is not checked, the Screen component behaves like a VerticalArrangement whose Height property is specified in pixels.
VerticalArrangement
In a VerticalArrangement, components ar...
Convert list to array in Java [duplicate]
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Maybe set the correct size of the array, as you obviously know it
– Oskar Kjellin
Jul 3 '13 at 11:25
7
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Determining 32 vs 64 bit in C++
...rs use for determining if it's a 64 bit environment or not and use that to set my variables.
// Check windows
#if _WIN32 || _WIN64
#if _WIN64
#define ENVIRONMENT64
#else
#define ENVIRONMENT32
#endif
#endif
// Check GCC
#if __GNUC__
#if __x86_64__ || __ppc64__
#define ENVIRONMENT64
#else
#define ...