Appendix C. Programming Concepts
A constant is a fancy word for a number or string of characters that never changes. Examples are
'communication'. The last two are called string constants. In ECMAScript, you can use either single or double quotes to mark the boundaries of a string. This is good if you ever need to write things like
"O'Reilly Media" or
'There is no "there" there.'
You will sometimes see the two Boolean constants
false, which are used for yes-or-no situations. ...