みたび間違えたよ
http://okwave.jp/qa/q9131681.html
idx=1 だよな
<!DOCTYPE html> <html> <meta charset="utf-8"> <title>q9131681.html</title> <body> <dl id="hoge"> <dd>222</dd> <dd>333</dd> <dd>AAA</dd> <dd>AAB</dd> <dd>BBB</dd> <dd>BBC</dd> <dd>CCC</dd> <dd>CCD</dd> </dl> <script> function firstCharType (e) { var t = e.textContent.charAt (0); return /\d/.test (t) ? '数値': t; } function appendDT (e, c, i) { var dt = e.ownerDocument.createElement ('dt'); dt.textContent = c + 'から始まる'; dt.id = 'list' + i; e.parentNode.insertBefore (dt, e); } var dd = Array.prototype.slice.call (document.querySelectorAll ('#hoge dd')); var cs = dd.map (firstCharType); for (var idx = 1, t = null, i = 0; c = cs[i]; i++) if (c !== t) appendDT (dd[i], c, idx++), t = c; </script>