what is the use of -> using namespace std;

Answer 1

Saurav Kumar this threads will clear your doubts
https://www.sololearn.com/discuss/33791/?ref=app
https://www.sololearn.com/discuss/1661959/?ref=app
https://www.sololearn.com/discuss/269267/?ref=app
https://www.sololearn.com/discuss/93433/?ref=app
https://www.sololearn.com/discuss/1821432/?ref=app

Answer 2

thanks