Question

Thanks for your attention and time.

I’m modifying an existing JavaScript but can’t understand a line of code. Please help me understanding this line:

 rowArray[i].value = rows[i].getElementsByTagName('td')[sortOn].firstChild.nodeValue;

I am clear till .getElementsByTagName('td'), sortOn is being passed in this function as a parameter. But I couldn’t understand [sortOn].firstChild.nodeValue;

Please guide me,

thanks

Answer 1

rows[i].getElementsByTagName('td') will get all td elements that are children of rows[i]. The [sortOn] part selects the td whose index is specified by the sortOn parameter. The .firstChild.nodeValue gets the text contained in the first element within that td.

Update: In the DOM, elements such as <td> can only contain other child elements, but they don’t have any text property. The text itself is contained in a special “text node” that is a child of the <td> node. This is why you use .firstChild to obtain the text node, then use .nodeValue to get the text contained in that node.