Whats the right way to use the JavaScript scope? -

Whats the right way to use the JavaScript scope? -

i have question. need know whats right way utilize javascript scope.

i have var this: var myvar; want create function modifies var. right way:

function a() {myvar = 12;} a();

or

function b(item) {item = 12;} b(myvar);

my goal is, dont want create myvar global.

the js way of modifying var not global, shared between multiple functions/blocks of code through utilize of closure:

var myfunc = (function() { var myvar = 1; homecoming function() { console.log(myvar++); }; }()); myfunc();//logs 1 myfunc();//logs 2 console.log(myvar);//<-- undefined, reference error

if, in snippet, variable used 2 functions, can write this:

var mymodule = (function() { var myvar = 1, mod = {};//object mod.funca = function() { console.log(myvar++); }; mod.funcb = function() { mod.funca();//or this.funca console.log(myvar); }; homecoming mod;//assign object mymodule }()); mymodule.funca();//logs 1 mymodule.funcb();//logs 2, first, logs 3 mymodule.funcb();//3, 4 console.log(mymodule.myvar);//undefined!

the beauty of value of myvar hidden. var can accessed through functions returned iife. there no global variable, no property, value does exist far funca , funcb concerned. rest of code can utilize var myvar without affecting how mymodule works.

how closures work, , how js resolves variable names have explained before. here's couple of links might useful you:

on closures. read through part of reply graphs this answer has useful links @ bottom.

javascript