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Unable to Cast from Parent Class to Child Class
I am trying to cast from a parent class to a child class but I get an InvalidCastException. The child class only has one property of type int. Does anyone know what I need to do?
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Does Java casting introduce overhead? Why?
Is there any overhead when we cast objects of one type to another? Or the compiler just resolves everything and there is no cost at run time?
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Integer division: How do you produce a double?
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double num = 5;
That avoids a cast. But you'll find that the cast conversions are well-defined. You don't have to guess, just check the JLS. int to double is a widening conversion. From §5.1.2:
Widening primitive conversions do not
lose informa...
C# “as” cast vs classic cast [duplicate]
I recently learned about a different way to cast. Rather than using
10 Answers
10
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'is' versus try cast with null check
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Because there's only one cast. Compare this:
if (myObj.myProp is MyType) // cast #1
{
var myObjRef = (MyType)myObj.myProp; // needs to be cast a second time
// before using it as a MyType
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}
to t...
Why does dividing two int not yield the right value when assigned to double?
...rsion, which returns a double, at least one of the ints must be explicitly casted to a double.
c = a/(double)b;
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How do I remove code duplication between similar const and non-const member functions?
...amp; get() const {
return c;
}
char & get() {
return const_cast<char &>(static_cast<const C &>(*this).get());
}
char c;
};
The two casts and function call may be ugly but it's correct. Meyers has a thorough explanation why.
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How can I reliably get an object's address when operator& is overloaded?
...f_impl
{
static inline T * f( T & v, long ) {
return reinterpret_cast<T*>(
&const_cast<char&>(reinterpret_cast<const volatile char &>(v)));
}
static inline T * f( T * v, int ) { return v; }
};
template<class T>
T * addressof( T & v ) {
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How to Concatenate Numbers and Strings to Format Numbers in T-SQL?
...o @my_int and it can't do that. Instead try:
SET @ActualWeightDIMS =
CAST(@Actual_Dims_Lenght AS VARCHAR(16)) + 'x' +
CAST(@Actual_Dims_Width AS VARCHAR(16)) + 'x' +
CAST(@Actual_Dims_Height AS VARCHAR(16))
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How does the socket API accept() function work?
... handle that socket.
In the early days of the ARPAnet, certain protocols (FTP for one) would listen to a specified port for connection requests, and reply with a handoff port. Further communications for that connection would go over the handoff port. This was done to improve per-packet performanc...