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Strictly speaking, no. All arguments in C are passed by value. However, when the argument being passed is a memory address, although the address itself is passed by value, we're effectively passing the object that resides at that address -- by reference.

Thus when a function's formal argument is a pointer variable (of any type), then it can be taken as read that the function is using the pass by reference semantic rather than the pass by value semantic. Nevertheless, it is important to keep in mind that the formal argument is assigned a copy of the actual argument and is therefore being passed by value.

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Is it possible in C plus plus builder xe to pass objects like TSQLConnection object to a dll as a parameter if yes then how?

Pass the object by reference to a function in the DLL.


Why pass by reference is quicker than pass by values in java?

Pass by Reference does not create a copy of the data items. So, it is faster.


What is actually passed to a function when an object is passed to a function through a pointer?

When an object is passed to a function by pointer, a copy of the pointer's value is passed to the function. Pointers are always passed by value, but because the value is a memory address than can be dereferenced, they enable us to pass objects by reference. In languages such as C which have no concept of references, this was the only way to pass by reference. C++ introduced proper references (aliases for existing objects), thus when we want to pass by reference we can choose to use a pointer or an actual reference. Normally we'd only pass by pointer when passing an optional argument that defaults to NULL when no argument is given. Otherwise we pass by reference because references can never be NULL.


Can a variable name can be passed to a value parameter in c plus plus?

No. Pass by value always receives a copy of the value being passed. Even if it were possible to physically pass a user-defined identifier into a function by value, the compiled code would not recognise the name since all identifiers are stripped out by the compiler and replaced with memory addresses. Strictly speaking, even pass by reference does not pass the variable name, as the function argument is simply an alias, an alternate but informal name, for the formal name you actually pass. In essence you are passing the memory address of the variable, rather the value of the memory address as you would with pass by value.


What is an alias name given to a variable in opp with c plus plus?

An alias is a reference, an alternate name for a variable or constant. You can assign the address of any variable or constant to a reference of the same type. A reference is a bit like a constant pointer to the type but, unlike a pointer, a reference has no address of its own thus you cannot store references. More importantly, references can never be NULL. They are simply an alternative name by which you can refer to an existing variable or constant. When you assign a value to an existing reference to a variable, you are assigning the value to the variable itself. When you pass a reference to a function, you are passing the address of the value being referred to, and that address is assigned to the function's reference argument and is local to the function. This is not unlike passing a pointer, but pointers may be NULL, references are guaranteed to be non-NULL (a NULL reference invalidates your program). Note that C++ references are not the same as C reference variables or constants. In C, a reference variable is simply a non-const pointer, while a reference constant is a constant pointer. Hence pointers can be dereferenced (both in C and C++). But in C++, a reference is neither a variable nor a pointer, but is constant (it always refers to the same object and cannot be reassigned once assigned).

Related Questions

What are the different parameter passing methods used by c plus plus?

Pass by value, constant value, reference and constant reference. Pass by value is the default in C++ (pass by reference is the default in Java).


How do you do a pass by reference in C with explanation?

Not possible, but you can still pass addresses.


What is a call by reference?

In C++ (C Plus Plus), when you call by reference, you are directly accessing the data of the referenced object. When you pass an object to a function by reference, any and all alterations to the object made within the function carry through to the actual object.


What is calling by reference?

In C++ (C Plus Plus), when you call by reference, you are directly accessing the data of the referenced object. When you pass an object to a function by reference, any and all alterations to the object made within the function carry through to the actual object.


Is it possible in C plus plus builder xe to pass objects like TSQLConnection object to a dll as a parameter if yes then how?

Pass the object by reference to a function in the DLL.


Why pass by reference is quicker than pass by values in java?

Pass by Reference does not create a copy of the data items. So, it is faster.


What is actually passed to a function when an object is passed to a function through a pointer?

When an object is passed to a function by pointer, a copy of the pointer's value is passed to the function. Pointers are always passed by value, but because the value is a memory address than can be dereferenced, they enable us to pass objects by reference. In languages such as C which have no concept of references, this was the only way to pass by reference. C++ introduced proper references (aliases for existing objects), thus when we want to pass by reference we can choose to use a pointer or an actual reference. Normally we'd only pass by pointer when passing an optional argument that defaults to NULL when no argument is given. Otherwise we pass by reference because references can never be NULL.


If you got a c plus and you need a c do you pass?

Yes, if you need a C to pass, and you have a C+, you pass.


What type of cell reference is c?

C is not a cell reference. C is a column reference, but you would need a row number to add to it to make a cell reference, like C2 or C35 or C527 etc.


How do you combine call by value and call by reference programs in c?

Very easily: there is no call-by-reference in C.


What type of cell is C?

C is not a cell reference. C is a column reference, but you would need a row number to add to it to make a cell reference, like C2 or C35 or C527 etc.


Is array list value type or reference type?

Arrays are reference type. array values are always pass by reference.