Question

write a program in c++ to swap the value of teo integer variable using call by reference method​

Answer 1

Answer:

include<iostream>

void swap(int *,int *);

int main ( )

{

int a,b;

a=10;

b=20;

cout<<"a="<<a<<" b="<<b;

swap (&a,&b);

cout<<"\na="<<a<<" b="<<b;

getch ();

return 0;

}

void swap(int *a,int *b)

{

*a = *a - *b; //storing difference

*b = *b + *a; //adding difference

*a = *b - *a; //subtracting difference

}

Adding to Amber Anand's answer

Swapping without third variable.

let a = 5 & b= 2 from

*a = *a - *b; //storing difference

*b = *b + *a; //adding difference

*a = *b - *a; //subtracting

a = 5 – 2; // now a=3

b = 2 + 3; //b=5

a = 5 – 3; // a=2

You can try this for other numbers to get firm understanding of the concept.

hope this helps…

Footnotes

Explanation:

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