How do I count the number of tr elements within a table using jquery.

This can be a most basic question, but it may keep us busy us for hours wasting our time.

Use a selector that will select all the rows and take the length.

var rowCount = $('#myTable tr').length;

Note: this approach also counts all trs of every nested table!

$('#myTable tr').size() will return the same value

the docs indicate that length is preferred over size() because it's faster