alert(process_stage1[1])  returns undefined.

Why???   

stage0 =["a", "b", "c", "d"];

-----------------[code] -------------------------------------------

   var stage_status = 'initial_stage';
 
   if(stage_status=='initial_stage'){

    var init = stage0.splice(0, 3);
                                                   
     process_stage1.push(init);

     alert(process_stage1[1]); // undefined??? Why???
    

} //if