Need to convert result of [removed] to number on javascript

Question

I have a html that contains tables like the following example

Answer 1

Try something like this, using a more functional approach:

var sum = [].map.call(valuelements, function(v) {
  return +v.textContent; }).reduce(function(a, b) { return a + b; });

Answer 2

You need to initialize counter with a starting number, otherwise you're performing math on undefined.

var counter = 0;

And then in the loop, use parseInt, parseFloat, or a direct number conversion on the .innerHTML value.

var counter = 0;

for (var i=0; i<features.length; i++){ 
  counter += parseFloat(valuelements[i].innerHTML);
}

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In a modern browser, you could do this:

var count = [].reduce.call(valueelements, function(c, v) {
    return c + parseFloat(v.innerHTML);
}, 0);