Question

我试图添加每张图片的大小，因此它保存在一个变量中。到目前为止我有这个：

var totalHeight;
var addHeight = $(this).height();

$('.img').each(function(i){
    totalHeight = totalHeight + addHeight;  
    console.log(totalHeight);
});

http://jsfiddle.net/tmyie/dKjcc/1/

但是，console.log正在报告NaN。有谁知道为什么？

Answer 1

var totalHeight = 0;

$('.img').each(function(i){
   totalHeight += $(this).height();
});

进一步说明：您想要使用的 this 是与选择器“.img”匹配的元素。你现在拥有的，var addHeight = $（this）.height（）是全局对象窗口的（高度）

console.log(this === window);

了解使用关键字this at MDN或learn jQuery

Answer 2

您需要设置var totalHeight = 0;

Answer 3

走你最初去的路线：

var totalHeight = 0;

$('.img').each(function(index, element){
    totalHeight = totalHeight + element.clientHeight;   
});

Answer 4

普通JavaScript：

function heights(element)
{
  var sum = 0;
  for (var i = 0; i < element.length; i++)
  {
    sum += element[i].clientHeight;
  }
  document.write(sum);
  return sum;
}

var imageArr = document.getElementsByClassName('img');
heights(imageArr);

Answer 5

Try this    
 <pre><code>
    var totalHeight=0;
    var addHeight = $(this).height();

    $('.img').each(function(i){
        totalHeight = totalHeight + addHeight;  
        console.log(totalHeight);
    });
    </pre></code>

添加每个图像的大小

5 个答案: