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Combining C++ and C - how does #ifdef __cplusplus work?
...acy C code. We've started writing in C++, with the intent to eventually convert the legacy code, as well. I'm a little confused about how the C and C++ interact. I understand that by wrapping the C code with extern "C" the C++ compiler will not mangle the C code's names, but I'm not ent...
What are the differences between a pointer variable and a reference variable in C++?
...
A pointer can be re-assigned:
int x = 5;
int y = 6;
int *p;
p = &x;
p = &y;
*p = 10;
assert(x == 5);
assert(y == 10);
A reference cannot, and must be assigned at initialization:
int x = 5;
int y = 6;
int &r = x;
...
How can I declare and define multiple variables in one line using C++?
...
int column = 0, row = 0, index = 0;
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Array_merge versus + [duplicate]
..., array_merge() concat index-array values.
If not, the index-array will to convert to values array, and then convert to assoc array.
Now it got two assoc array and merge them together, when key conflict, right(last) value will be kept.
array_merge(null, array()) returns array() and got a warning sai...
Int division: Why is the result of 1/3 == 0?
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The two operands (1 and 3) are integers, therefore integer arithmetic (division here) is used. Declaring the result variable as double just causes an implicit conversion to occur after division.
Integer division of course returns the true result of divisi...
How do I generate random integers within a specific range in Java?
How do I generate a random int value in a specific range?
66 Answers
66
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Macro vs Function in C
...ample, this macro:
#define square(a) a * a
works fine when used with an integer:
square(5) --> 5 * 5 --> 25
but does very strange things when used with expressions:
square(1 + 2) --> 1 + 2 * 1 + 2 --> 1 + 2 + 2 --> 5
square(x++) --> x++ * x++ --> increments x twice
Putt...
Plotting time in Python with Matplotlib
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You must first convert your timestamps to Python datetime objects (use datetime.strptime). Then use date2num to convert the dates to matplotlib format.
Plot the dates and values using plot_date:
dates = matplotlib.dates.date2num(list_of_d...
Explicit specialization in non-namespace scope [duplicate]
...ion:
namespace detail {
template <typename TL> void Verify (int, int[]) {}
template <> void Verify<int>(int, int[]) {}
}
template<typename T> class CConstraint {
// ...
template <typename TL> void Verify(int position, int constraints[]) ...
How can I record a Video in my Android App.?
...der.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
finish();
} catch (IOException e) {
e.printStackTrace();
finish();
}
}
public void onClick(View v) {
if (recording) {
recorder....