废话不多说，直接给大家贴代码了。
具体代码如下所示：
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta charset="utf-8">
<title>点击按钮文字变成input框，点击保存变成文字</title>
<style type="text/css">
table{ text-align: center; font-size: 14px;}
table>thead>tr>th{ font-weight: normal;}
.text-right{ padding-right:73px; text-align: right;}
.text{ width: 50px; height: 30px; border: 1px solid #ddd; text-align: center;}
</style>
<script type="text/javascript" src="js/jquery.min.js"></script>
</head>
<body>
<table>
<thead>
<tr>
<th width="400">品名</th>
<th width="200">件数</th>
</tr>
</thead>
<tbody>
<tr height="50">
<td>iPhone6s</td>
<td class="edit">2</td>
</tr>
<tr height="50">
<td>小米5</td>
<td class="edit">5</td>
</tr>
</tbody>
<tfoot>
<tr>
<td colspan="2" class="text-right">
<button type="button" class="btn" onclick="change(this)">修改</button>
</td>
</tr>
</tfoot>
</table>
<script type="text/javascript">
function change(obj){
var xg=$(obj).html();
if(xg=='修改'){
$('.edit').each(function(){
var old=$(this).html();
$(this).html("<input type='text' name='editname' class='text' value=" old " >");
})
$(obj).html('保存');
}else if(xg=='保存'){
$('input[name=editname]').each(function(){
var old=$(this).html();
var newfont=$(this).parent('td').parent('tr').children().find('input').val();
$(this).parent('td').html(newfont);
})
$(obj).html('修改');
}
}
</script>
</body>
</html>