Undefined
undefined
Null
null
Boolean
true
and false
String
Number
double
in JavaNaN
, +Infinity
, -Infinity
, and -0
Object
Arrays and functions are considered to be objects.
typeof
"undefined"
"boolean"
"string"
"number"
"function"
"object"
null
is considered an object here<!doctype html> <html> <head> <meta charset="utf-8"/> <title>Program X</title> </head> <body> <h1>Program X</h1> <pre> <script src="programX.js"> </script> </pre> </body> </html>
document.writeln('Program X') ;
prompt(S)
An illustration of an anonymous and inner function that requires a closure.
function curryadd(m) { return function(n) { return m + n ; } ; }
function fact(n) { if (!n) { return 1 ; } else { return n*fact(n-1) ; } }
// Example from http://amix.dk/blog/post/19239 function facMaker(fn) { return function(n) { return n == 0 ? 1 : n * fn(fn)(n - 1); } } document.writeln(facMaker(facMaker)(10)) ;
function Y(dn) { return function(fn) { return fn(fn); }(function(fn) { return dn(function(x) { return fn(fn)(x); }); }); } function fac4Y(fn) { return function(n) { return n == 0 ? 1 : n * fn(n - 1); } } ; document.writeln(Y(fac4Y)(10)) ;