Write a program to input a string and replace all the occurrences of character T with @

Answer 1

Just do :

replace(str.begin(), str.end(), 'T', '@');

// Basically does the same thing
// as a for loop used to replace
// each character.

Answer 2

https://code.sololearn.com/cZAtENqKljG8/?ref=app

Answer 3

To see how it works:

for (char &c : str)
if (c == 'T')
c = '&';