Custom Calculation Script - Adobe Acrobat

[J.Doe09]

Greetings! I’m creating a rating form in Adobe Acrobat that has several fields in each section. Each field has a dropdown menu with the following options: (Choose one, N/A, 1, 2, 3, 4, 5). If I choose N/A or leave it as “Choose one,” Adobe sees it as zero and includes it in the average rating, lowering the overall score. What formula do I create so that only the numbers get averaged out? 

Please note: I looked at other similar questions, but suggested formulas did not work for me. Help! 

[try67]

Let's say the question fields are called Q1 to Q10. You can then use this code as the custom calculation script of your average field:

var total = 0;
var n = 0;
for (var i=1; i<=10; i++) {
	var v = this.getField("Q"+i).valueAsString;
	if (v!="Off" && v!="N/A") {
		n++;
		total+=Number(v);
	}
}
if (n==0) event.value = "";
else event.value = total/n;

[J.Doe09]

This worked! But NaN is now showing up in the area where I would like it blank (where the average is supposed to appear). How do I fix this? 

[try67 · Accepted solution]

That means some of the values of the fields could not be converted to a number.

Are you sure the value is actually "N/A" and not something else? To avoid such issues change these two lines:

var v = this.getField("Q"+i).valueAsString;
if (v!="Off" && v!="N/A") {

To:

var v = Number(this.getField("Q"+i).valueAsString);
if (!isNaN(v)) {