JavaScript data types (typed values)

data-types.js

var a;
typeof a;               // "undefined"

a = "hello world";
typeof a;               // "string"

a = 42;
typeof a;               // "number"

a = true;
typeof a;               // "boolean"

a = null;
typeof a;               // "object" -- weird, bug

a = undefined;
typeof a;               // "undefined"

a = { b: "c" };
typeof a;               // "object"

-------------------------------------------------------------

a = [];
typeof a;               // object

a = function() {};
typeof a;               // function