do块内输入'< - '的解析错误？(Parse Error on Input '<-' inside a do block?)

 为什么你在锚中写ss.php你不需要那就是为什么它在点击时重定向ss.php并获得错误未定义的索引。 
 
 你的HTML代码应该是这样的： 
 
<form id="myForm" method="post" action="ss.php">
    <div class="img">            
        <img id="theme_bg" src="images/themes/theme1.jpg">
        <input name="imgpath" id="imgpath" type="hidden"/>
    </div>
</form>
 
 Jquery代码： 
 
$(document).ready(function ($) {
        $('.img').on('click', 'img', function () {
            var imgsrc = $(this).attr('src');
            $("#imgpath").val(imgsrc);       //this is returning the img src correctly 
            $("#myForm").submit();
        });
});
 
 ss.php 
 
 <?php
   $imagepath = $_POST['imgpath'];
   echo $imagepath;
?>

Why you wrote ss.php in anchor you dont need that that's why it redirecting ss.php on click and getting error undefined index.
 
Your html code should be like this:
 
<form id="myForm" method="post" action="ss.php">
    <div class="img">            
        <img id="theme_bg" src="images/themes/theme1.jpg">
        <input name="imgpath" id="imgpath" type="hidden"/>
    </div>
</form>
 
Jquery code:
 
$(document).ready(function ($) {
        $('.img').on('click', 'img', function () {
            var imgsrc = $(this).attr('src');
            $("#imgpath").val(imgsrc);       //this is returning the img src correctly 
            $("#myForm").submit();
        });
});
 
ss.php
 
 <?php
   $imagepath = $_POST['imgpath'];
   echo $imagepath;
?>