javascript - For Loop not working -

i want function add 2 values inputted form instead of adding values merges number. if input 2 , 2 comes 22, whereas want 4 outputted. take loop not wotking

<script> var calculate = function(){ var input = document.getelementsbytagname("input"); var length = input.length; (var = 0; < length; i++) {   input[i] = input[i].value;   input[i] = parseint(input[i]); } var total_living_room = input[0] + input[1]; document.getelementbyid("sh").innerhtml=total_living_room; } </script> 

the problem is, getelementsbytagname() returns nodelist , no array (see,e.g., mdn on this).

both behave similar in many ways, elements of nodelist can not changed in way do.

as solution parse values in second array , use that:

<script> var calculate = function(){   var input = document.getelementsbytagname("input"),       length = input.length,       inputvals = [];   (var = 0; < length; i++) {     inputvals.push( parseint( input[i].value, 10 ) );   }   var total_living_room = inputvals[0] + inputvals[1];   document.getelementbyid("sh").innerhtml=total_living_room; } </script> 

edit

example fiddle