javascript - How much space does the localstorage key itself take up? -

lets create localstorage key , give empty string. name of keyitem take same amount of space value per character?

for instance does

localstorage.setitem("keyitem","")  //equal space of other 1 under? localstorage.setitem("key","item"); 

also, amount of keys matter? instance

localstorage.setitem("key",""); //equal amount of storage 3 under combined?  localstorage.setitem("k",""); localstorage.setitem("o",""); localstorage.setitem("h",""); 

i found function once calculate size of localstorage , sessionstorage objects, can't remember found it.

here's code:

storage.prototype.size = function(units) {     'use strict';     units = units ? units.touppercase() : 'mb';     var size = unescape(encodeuricomponent(json.stringify(this))).length;     switch (units) {         case 'b': return [size,'b'].join(' ');         case 'kb': return [+(size / 1024).tofixed(3),'kb'].join(' ');         default: return [+(size / 1024 / 1024).tofixed(3),'mb'].join(' ');     } }; 

i decided go ahead , run tests in various browsers.

firefox (37.0.2):

chrome (42.0.2311.90 m):

ie 11 (11.0.9600.17420):

opera (29.0.1795.47):

so looks firefox, chrome, , opera (probably safari well, don't have that) have same behavior, , keys take far more space values.

in ie (good old ie...), implementation executed in way such doesn't matter how store something.