Confused with call by reference...

I am confused how another method of function call by reference works...withought using the pointer....
the method uses reference parameters in function header....as
int anyfunction( int &var)
and simply variable name is used for all work in the function..
as for this function header the var can be used as
var = var*var;

can any one explain why this can be done...?

call by reference like

Code:

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int func (int& var) { var = var + 1; }

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and call by reference like

Code:

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int func (int* var) { *var = *var + 1; }

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are essentially the same. the difference lies not in the program executable in the end, but in the compiler. C++ allows the use of variables with references pointing to previous variables only in the scope of a function. this is an improvement on C, in an effort by the creators of C++ to avoid excessive pointer use in functions.

in other words, this is a handy feature included in C++ to make writing programs easier, but it doesn't compile to anything different than by using pointers instead.

Can I ask which method is frequently... used.. by good programmers....

Quote:

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Originally posted by jawwadalam
Can I ask which method is frequently... used.. by good programmers....

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the C method of passing a pointer to simulate call by refrence is considered depreciated in C++. pointers still have legit uses, but this is no longer one of them.

Note: it's not which is common... it's when do you need to use it, calling by refrence prevents the creating a copy of the variables when you call by value, and it's useful when you pass larg objects.
if you want to pass by refrence

Code:

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int func (const int& var)

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so if so make any changes the compiler will give you a compile time error.