Does assigning a function handler in JavaScript create a copy or just a reference? -

i'd make sure can use function handler without generating copy every time assigned handler.

i have class handler such as:

snapwebsites.editor.prototype._someprivatefunctionhandler = function(e) { ... } 

then read blob file received drag & drop:

... .on("drop", function(e) {     // [...snip...] -- have tests , loop through files ,     //                 on each file:     r = new filereader;     r.onload = snapwebsites.editor.prototype._someprivatefunctionhandler;     r.readasarraybuffer(e.originalevent.datatransfer.files[0]) } ... 

when assign _someprivatefunctionhandler function onload handler of filereader, creating full copy of function or reference?

you creating reference. demonstrate:

var xyz = function() {}; var abc  = xyz; xyz.someproperty = 1; abc.someproperty; /=> 1