Assuming that the following variables have been declared:

evaluate the following expressions:

a. str1.length()

b. str1.charAt(7)

c. str2.charAt(0)

d. str1.indexOf("o")

e. str2.toUpperCase()

f. str1.toLowerCase().indexOf("B")

g. str1.substring(4)

h. str2.substring(3, 14)

i. str2.replace("a", "oo")

j. str2.replace("gray", "white")

k. "str1".replace("r", "range")

// index 0123456789012345 String stri = "Frodo Baggins"; String str2 "Gandalf the GRAY";