For loop and using the Std: Reverse and transform

The program should be in "For loop":

1) If the first character of the letter is G, then skip the line and print nothing for that argument.

2) If the first character is the letter B, Then please print the letters in reverse order and also converting any lower case letters to upper case.

For .....

if (TestString[0] == 'G')
    print out....

else if (TestString[0] == 'B')

    std:: ... reverse(XXXX) 
  AND 
    std:: ... transform (XXXX)
else
    Printout
    TestString = "NONE";