instanceof for custom types:var ClassFirst = function () {};
var ClassSecond = function () {};
var instance = new ClassFirst();
typeof instance; // object
typeof instance == 'ClassFirst'; // false
instance instanceof Object; // true
instance instanceof ClassFirst; // true
instance instanceof ClassSecond; // false
typeof for simple built in types:'example string' instanceof String; // false
typeof 'example string' == 'string'; // true
'example string' instanceof Object; // false
typeof 'example string' == 'object'; // false
true instanceof Boolean; // false
typeof true == 'boolean'; // true
99.99 instanceof Number; // false
typeof 99.99 == 'number'; // true
function() {} instanceof Function; // true
typeof function() {} == 'function'; // true
instanceof for complex built in types:/regularexpression/ instanceof RegExp; // true
typeof /regularexpression/; // object
[] instanceof Array; // true
typeof []; //object
{} instanceof Object; // true
typeof {}; // object
And the last one is a little bit tricky:
typeof null; // object