From C to C++

reference: In C you can pass/return values to a function in 2 ways. 1. By value 2. By address (Using pointer). C++ introduces third way to return/pass values. It is called by reference. Reference is similar to a pointer but has following properties.

• One variable can have multiple references
• But a reference can refer to only one variable in its life time.
• Reference needs to be initialized (declared and defined in same line).
• You can't do int i; int &ref; ref = i;
• int i; int &ref = i;
• Reference are so tightly coupled that any change in one reflect in change in all others

Example:

int i = 10;

int &ref = i;

void funct_r(int &ref);

void funct_v(int val);

void funct_a(int *add);

...

...

main() {

int i = 10;

funct_r(i); // call by reference

funct_v(i); // call by value

funct_a(&i);

}

reference are more readable than pointers while for most part they work like pointers. Btw, it is also possible to create reference to a pointer.

e.g.

char *name = "India";

char *& ref = name; // Read from right to left... it says reference to a char *

Points to remember:

• We cannot have a array of references
• Never return local variable by reference