s1 = 
s2 = Hello, World
s3 = Welcome to Florida, have a nice day
s4 = 12345

Making the calls:
        cin >> s1
        getline(cin, s2, ',')
        getline(cin, s3)
Enter some sentences: John was here, but not there

New string values:
s1 = John
s2 =  was here
s3 =  but not there
---------------------------
result = DogFood
s1 = DogFood
s5 = The concatenation of the catapult is a catamaran
s5.indexOf("cat") returns 7
s5.indexOf("dog") returns -1
s5.getLength() = 48
s5[4] = c
s5[10] = e
s5[15] = o
s5[52] = ascii 0
s5.substring(10,16) = enation of the c
s5.substring(23) = e catapult is a catamaran
-----------------------------
words = Greetings, Earthling
words.getLength() = 20
words = Kreepings, Earthzing
words = Kreepings, Earthzing     Q
words = Kreepings, Insane Earthzing     Q
-----------------------------
x = apple
y = apply
x < y is true
x <= y is true
x != y is true