js 反向将table内容生成json

function TableToJson(tableid) {

var txt = "[";

var table = document.getElementById(tableid);

var row = table.getElementsByTagName("tr");

var col = row[0].getElementsByTagName("th");

for (var j = 1; j < row.length; j++) {

var r = "{";

for (var i = 0; i < col.length; i++) {

var tds = row[j].getElementsByTagName("td");

r += "\"" + col[i].innerText+ "\"\:\"" + tds[i].innerText+ "\",";

}

r = r.substring(0, r.length - 1)

r += "},";

txt += r;

}

txt = txt.substring(0, txt.length - 1);

txt += "]";

return txt;

}