how do i get the row (and its index) in an html table from a button click inside a cell in that row.

Question

question is in the subject

Answer 1

You have to go back up through the DOM until you find the <tr> element.

function onclick_handler( event ) {
    var element = event.target;
    while( element.tagName != 'TR' && element.parentNode ) {
        element = element.parentNode;
    }
    return element.rowIndex;
}

Answer 2

onclick="alert(this.parentNode.rowIndex);"

Unless you have a tbody type tag, then use parentNode twice. Or in jquery:

onclick="alert($(this).closest('tr').attr('rowIndex'));"

Answer 3

$("yourtableselector td").click(function() {
    alert($(this).parents("tr").get(0).rowIndex);
});