···1515// "undefined" should not be thought of as a value, but as a way
1616// of telling the compiler that you are not assigning a value
1717// _yet_. Any variable may be set to undefined, but attempting to
1818-// read its value before assigning one _always_ a mistake.
1818+// read its value before assigning one is _always_ a mistake.
1919//
2020// * null
2121//