how to know table rows in jquery code example

Example 1: jquery grab table row

$('.itemTable').eq(2);
//this will grab the 3rd row of the table with the class itemTable

Example 2: get table row data jquery

$("document").ready(function() {
  var tb = $('.layui-table:eq(0) tbody');
  var size = tb.find("tr").length;
  console.log("Number of rows : " + size);
  tb.find("tr").each(function(index, element) {
    var colSize = $(element).find('td').length;
    console.log("  Number of cols in row " + (index + 1) + " : " + colSize);
    $(element).find('td').each(function(index, element) {
      var colVal = $(element).text();
      console.log("    Value in col " + (index + 1) + " : " + colVal.trim());
    });
  });
});