oop - Class vs. static method in JavaScript -

i know work:

function foo() {}; foo.prototype.talk = function () {     alert('hello~\n'); };  var = new foo; a.talk(); // 'hello~\n' 

but if want call

foo.talk() // not work foo.prototype.talk() // works correctly 

i find methods make foo.talk work,

1. foo.__proto__ = foo.prototype
2. foo.talk = foo.prototype.talk

is there other ways this? don’t know whether right so. use class methods or static methods in javascript code?

first off, remember javascript prototypal language, rather class-based language¹. foo isn't class, it's function, object. can instantiate object from function using new keyword allow create similar class in standard oop language.

i'd suggest ignoring __proto__ of time because has poor cross browser support, , instead focus on learning how prototype works.

if have instance of object created function² , access 1 of members (methods, attributes, properties, constants etc) in way, access flow down prototype hierarchy until either (a) finds member, or (b) doesn't find prototype.

the hierarchy starts on object called, , searches it's prototype object. if prototype object has prototype, repeats, if no prototype exists, undefined returned.

for example:

foo = {bar: 'baz'}; alert(foo.bar); //alerts "baz"  foo = {}; alert(foo.bar); //alerts undefined  function foo(){} foo.prototype = {bar: 'baz'}; f = new foo(); alert(f.bar); //alerts "baz" because object f doesn't have attribute "bar" //so checks prototype f.bar = 'buzz'; alert( f.bar ); //alerts "buzz" because f has attribute "bar" set 

---

it looks me you've @ least understood these "basic" parts already, need make them explicit sure.

in javascript, object³.

everything object.

function foo(){} doesn't define new function, defines new function object can accessed using foo.

this why can access foo's prototype foo.prototype.

what can set more functions on foo:

foo.talk = function () {   alert('hello world!'); }; 

this new function can accessed using:

foo.talk(); 

i hope you're noticing similarity between functions on function object , static method.

think of f = new foo(); creating class instance, foo.prototype.bar = function(){...} defining shared method class, , foo.baz = function(){...} defining public static method class.

---

_{1: class "future reserved word" in ecmascript 5 specification, es6 introduces ability define classes using class keyword.}

_{2: class instance created constructor, there many nuanced differences don't want mislead you}

_{3: primitive values—which include undefined, null, booleans, numbers, , strings—aren't technically objects because they're low-level language implementations. booleans, numbers, , strings still interact prototype chain though objects, purposes of answer, it's easier consider them "objects" though they're not quite.}