All functions, in JavaScript, are first-class: They can coexist with, and can be treated like, any other JavaScript object
Anonymous functions are typically used in cases where you wish to create a function for later use
function isNimble(){ return true; }
var canFly = function(){ return true; };
window.isDeadly = function(){ return true; };
1, anonymous storing it as a property to an object
var obj = {
someMethod: function(){
return true;
} };
2 use anonymous as a callback
setInterval(function(){
// An anonymous function called every 100 milliseconds
}, 100);
3 recursion for anonymous
var ninja = {
yell: function(n){
return n > 0 ? ninja.yell(n-1) + "a" : "hiy";
} };