Completed test 70: test_strings_are_unique_objects

The lesson of this test? Given:
a = "a string"
b = "a string"

a == b
but
a.object_id != b.object_id

The have the same values but are different objects.
Test 71 completed: test_symbols_are_symbols

Given:
symbol = :ruby
Then:
symbol.is.a?(Symbol) == true
Test 72 completed: test_symbols_can_be_comared

Given:
symbol1 = :a_symbol
symbol2 = :a_symbol
symbol3 = :something_else
Then:
symbol1 == symbol2
symbol2 != symbol3
Test 73 completed: test_identical_symbols_are_a_single_internal_object

Given:
symbol1 = :a_symbol
symbol2 = :a_symbol

You have two variables but only object. symbol1 and symbol2 are two names for the same object.

symbol1.object_id == symbol2.object_id
Test 74 passed: test_method_names_become_symbols

Lesson learned and answer to "THINK ABOUT IT":
Why do we use "Symbol.all_symbols.map { |x| x.to_s } ? Why do this to test whether there is a "test_method_names_become_symbols" symbol?

We do this because even if there was no "test_method_names_become_symbols" symbol, if we wrote:
assert_equal true, Symbol.all_symbols.include?(:test_method_names_become_symbols)
That very act would create the symbol we were looking for. So we use Symbol.all_symbols to get an array of all the symbols currenly in Ruby's symbol table, use the .map block to convert each to a string value which goes in our array, then test for the string version of the symbol we're looking for. This way, if the symbol doesn't exist before testing for it, we won't accidentally create it.
Test 75 Completed: test_constants_become_symbols

This test shows that constants do indeed become symbols, to sum up:
  RubyConstant = "What is the sound of one hand clapping?"
  all_symbols_as_strings = Symbols.all_symbols.map { |x| x.to_s }
  all_symbols_as_strings.include?("RubyConstant") == true

As with Test 74, we convert the array of symbols to an array of strings, this way we can test for a RubyConstant symbol without accidentally creating it.
Test 76 completed: test_symbols_can_be_made_from_strings

You can indeed create a symbol from a string. Given:
  thisIsAString = "YoHoHo"
You can do either of:
  thisIsAString.intern
  thisIsAString.to_sym
Either results in the symbol :YoHoHo being created.
Test 77 Completed: test_symbols_with_spaces_can_be_built

Given:
symbol = :"cats and dogs"

A new symbol is created that is the full string within parenthesis.