You can think of character classes as characters with special meaning. They are recognized as special when you place the \ before the character. The . is the only exception. It requires no \ and it is a wildcard character. It matches any character except for line terminators.
ES2018 added the s "dotAll" flag, which allows the dot to also match line terminators.
Here are a list of the characters classes in JavaScript:
., \cX, \d, \D, \f, \n, \r, \s, \S, \t, \v, \w, \W, \0, \xhh, \uhhhh, \uhhhhh, [\b]
const str = "eta, edu, etc, ele, epa, eye, exe, emf, ete, eon, era"
// Instead of a string we want an array like this:
// ["eta", "edu", "etc", "ele", "epa", "eye", "exe", "emf", "ete", "eon", "era"]
// You could use the split() method but let's try with a regular expression.
Write the regular expression that returns an array of all words. Use the character class . in your expression.