js实现
<html> <head> <title>求列和</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> </head> <body onload="sum()"> <table id="ddd"> <tr><td>2</td><td>3</td><td>4</td></tr> <tr><td>2</td><td>3</td><td>4</td></tr> <tr><td>2</td><td>3</td><td>4</td></tr> </table> <script language="javascript" type="text/javascript"> function sum(){ var second = 0; var third = 0; var trObj = document.getElementsByTagName('tr'); for(var i = 1; i<=trObj.length; i++){ for(var j =1;j<=trObj[i-1].getElementsByTagName('td').length;j++) { if(j%2==0) second+=parseInt(trObj[i-1].getElementsByTagName('td')[j-1].innerHTML); if(j%3==0) third+=parseInt(trObj[i-1].getElementsByTagName('td')[j-1].innerHTML); } } alert("第二列和为："+second); alert("第三列和为："+third); } </script> </body> </html>
jquery实现
<!DOCTYPE html> <html> <head> <title>求列和</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <script src="js/jquery-1.3.2.min.js"></script> <script language="javascript" type="text/javascript"> $(document).ready(function(){ var second=0; var third=0; // $("tr td:nth-child(2)") ; $("tr td:nth-child(2)").each(function (i){ second+=parseInt($(this).html()); }); $("tr td:nth-child(3)").each(function(i){ third+=parseInt($(this).html()); }); alert("第二列和为"+second); alert("第三列和为"+third); }); </script> </head> <body> <table id="ddd"> <tr><td>2</td><td>3</td><td>4</td></tr> <tr><td>2</td><td>3</td><td>4</td></tr> <tr><td>2</td><td>3</td><td>4</td></tr> </table> </body> </html>