Structure as Pointer

(i) By Using Call by Using Value

int area(struct Rectangle r1)
{
    r1.length;
    return r1.length * r1.breadth;
}
    int  main()
    {
          struct Rectangle r={10,5};
           prinf("%d",area(r));
    }

output

 50

(ii) Call By Reference:

int area(struct Rectangle &r1)
{
    r1.length;
    return r1.length * r1.breadth;
}
    int  main()
    {
          struct Rectangle r={10,5};
           prinf("%d",area(r));
    }

output

  55

(iii) Call By Address:

struct Rectangle
{
    int breadth;
    int length;
};
      void changeLength(struct Rectangle *p, int l)
{
      p->length=l;
}
int main()
{
      struct Rectangle r={10,5};
       changeLength (&r,20);
}

output

55