Concepts of bob

General

functions: used as the main entry point for the exercise
function arguments: input message is passed as an argument
function return value: Bob's response
arrow-function: used as a default in the skeleton file and also used for deciding if a message is of a certain type
modules: used for exporting the main function in order to be imported and called from unit tests
scoping: using { } to define scope (for functions and for conditionals)
variables: used for declaring a trimmed message, and also for declaring the arrow functions
strings: used as input and output of the function (escaped single-quote character inside string literal and also using methods and properties of String e.g. length, trim, endsWith, toUpperCase)
regular expressions: used for pattern matching (also using the test method of RegExp object)
sameness: used '===' to check the length of a string and also to check if a string is uppercase
boolean logic: used '&&' operator for checking that two conditions are fulfilled at the same time
conditionals: if-else - used for checking which type of message did Bob received and also to decide Bob's response
duck typing: using duck typing whenever methods or properties of String object are called

switch statement: used as an alternative to if-else statements for identifying the type of message