StringTest

1. What is the knowledge point of the test? Where is the official document to the knowledge point?
   • Official Document: https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html
   • Learning of Optional Class
     • Strings are immutable
     • String builder
   • String manipulation
   • String unicode
2. Why the test failed at first?
   • The expected values are incorrect
3. Why you corrected the test that way?
   • I initialized the value of Optional Boolean from Optional.empty() to Optional.of(true||false)
   • Get the index of the expectedString and used substring to get the expected output.
   • Split string by whitespace or forward slash and store in an array
   • Used nested for loop to design the expected output and string builder to store characters.
   • For loop to checksum of each character in a string
   • Initialized the expected output string Unicode to display Nihongo characters
   • Add string builder to store characters and used for loop to get the last character to first character
   • Initialized value with string format and change and concatenate the format classifier as variable.
4. Do you have further questions on this knowledge point?
   • None