javascript - 如果图像存在于product_image 1到4 boject路径中，如何使用javascript获取长度

Question

在网络服务1中就像这样

                  "product_image1":"http://XYZ.co.uk/product_img/big/1_14238411703234.JPG" ,
                 "product_image2":"http://XYZ.co.uk/product_img/big/2_14238411703234.JPG" ,
                 "product_image3":"http://XYZ.co.uk/product_img/big/",  
                 "product_image4":"http://XYZ.co.uk/product_img/big/", 

在 webservice 2 中就像这样

"product_image1":"http://XYZ.co.uk/product_img/big/1_14303945253625.jpg" ,
                  "product_image2":"http://XYZ.co.uk/product_img/big/2_14303945253625.jpg" ,
                  "product_image3":"http://XYZ.co.uk/product_img/big/3_14303945253625.jpg",  
                  "product_image4":"http://XYZ.co.uk/product_img/big/4_14303945253625.png",

我的代码:-

 items+='<img id="slideImgId3" src='+item.product_image1+' class="detailShowBigImg">';


                 items+='<img src='+item.product_image1+'  onclick="changeImage3(\''+item.product_image1+'\');" class="multiImgShow">';
                 items+='<img src='+item.product_image2+'  onclick="changeImage3(\''+item.product_image2+'\');" class="multiImgShow">';
                 items+='<img src='+item.product_image3+'  onclick="changeImage3(\''+item.product_image3+'\');" class="multiImgShow">';

 <script type="text/javascript">
  function changeImage3(img3)
  {
    document.getElementById("slideImgId3").src=img3;
  }
</script>

你可以看到webservice 1和webservice 2。在webservice 1中，product_image3和product_image4没有图像，而在webservice 2中，所有对象图像都在那里，那么如何解决这个问题并使其动态。

Answer 1

尝试这组代码

var img = document.getElementById('imageid'); 
//or however you get a handle to the IMG
var width = img.clientWidth;
var height = img.clientHeight;