Welcome to DrJava.  Working directory is C:\Users\rlkraft
> System.out.println("How are you?")
How are you?
> "hello".length()
5
> "bye".length()
3
> "hello".toUpperCase()
"HELLO"
> "bye".toUpperCase()
"BYE"
> String s1 = "hello"
> s1.length()
5
> s1.toUpperCase()
"HELLO"
> s1
"hello"
> s1.charAt(2)
'l'
> s1.charAt(4)
'o'
> s1.charAt(0)
'h'
> String s2 = "How are you?"
> s2
"How are you?"
> s2.length()
12
> s2.charAt(12)
java.lang.StringIndexOutOfBoundsException: String index out of range: 12
        at java.lang.String.charAt(Unknown Source)
> s2.charAt(11)
'?'
> s2.charAt(3)
' '
> s1.charAt(3)
'l'
> s2.endsWith("??")
false
> s2.endsWith("u?")
true
> s2.indexOf("are")
4
> s2.indexOf("Are")
-1
> s1.replace("l", "k")
"hekko"
> s1
"hello"
> s1.replace("l", "bob")
"hebobbobo"
> s1.replace("ll", "2")
"he2o"
> s1.replace("lll", "2")
"hello"
> "helllo".replace("ll", "2")
"he2lo"
> "hellllo".replace("ll", "2")
"he22o"
> s2
"How are you?"
> s2.substring(2, 5)
"w a"
> s2.substring(8, s2.length())
"you?"
> s2.substring(2, s2.length())
"w are you?"
>