javascript \w
\w
//This shortcut is equal to [A-Za-z0-9_].
//This character class matches upper and lowercase letters plus numbers.
//Note, this character class also includes the underscore character (_).
let longHand = /[A-Za-z0-9_]+/;
let shortHand = /\w+/;
let numbers = "42";
let varNames = "important_var";
longHand.test(numbers); // Returns true
shortHand.test(numbers); // Returns true
longHand.test(varNames); // Returns true
shortHand.test(varNames); // Returns true