Javascript code with 2 classes and issue -

i have 1 issue javascript code of clicking buttons in 1 page.

to have code

var el = document.getelementsbyclassname('a');  (var i=0;i<el.length; i++) {           el[i].click();  } 

but code clicks 1 button, leaves 1 one unclicked , after clicks 3rd button etc. (it goes 1 click leaves 1 , click other.)

my first problem , second problem that

if run again code clicks clicked buttons. has no point.

therefore checked when button clicked, class affected. , i'm trying code see if working doesnt.

var el = document.getelementsbyclassname('num_button');  var ele = document.getelementsbyclassname('num_clicked');  (var i=0;i<el.length; i++) {     if ( ele != 1)         {          el[i].click();         } } 

but not working @ all. still clicks button has been clicked.

any solution??? thanks!

edit 1: here html code before click

<div class="stats_wrapper num_stats_wrapper ">             <span class=" num_button  num_stats_span sprite_icon">             </span>                <span class="count num_count  num_popup_button ">                 13               </span>           </div> 

html code after click

<div class="stats_wrapper num_stats_wrapper num_clicked ">             <span class=" num_button  num_stats_span sprite_icon">             </span>                <span class="count num_count  num_popup_button ">                 14               </span>           </div> 

i believe issue caused changing button class name, , modifying live collection of nodes.
resolve issue can "transform" nodes array , apply click code:

var el = document.getelementsbyclassname('a'); var arr = array.prototype.slice.call(el); (var i=0; i<arr.length; i++) {   arr[i].click(); } 

for second issue (if understand correctly) want click buttons has not been clicked before.

var el = document.getelementsbyclassname('num_button');  (var i=0; i<el.length; i++) {    var ele = el[i];    if (ele.parentnode.classname.indexof('num_clicked') == -1) {      ele.click();    } }