获取他们的位置，并使用毕达哥拉斯定理来确定他们之间的距离...

 （function（）{

 var getPositionAtCenter = function（element）{
 var data = element.getBoundingClientRect（）; 
返回{
x：data.left + data.width / 2，
y：data.top + data.height / 2 
}; 
}; 

 var getDistanceBetweenElements = function（a，b）{
 var aPosition = getPositionAtCenter（a）; 
 var bPosition = getPositionAtCenter（b）; 

返回Math.sqrt（
 Math.pow（aPosition.x  -  bPosition.x，2）+ 
 Math.pow（aPosition.y  -  bPosition.y，2）
）; 
}; 

 var distance = getDistanceBetweenElements（document.getElementById（x），
的document.getElementById（ Y））; 

}）（）; 
 

上（原点位于左上角），因此您可以想象一个右键菜单，

您可以修改方程以得到 c 的值， code>通过获得对方的平方根。

然后，您只需将值（ x 和 y 是元素之间的差异，一旦它们的中心被确定ned），你会发现斜边的长度，这是元素之间的距离。

If I have HTML elements as follows:

<div id="x"></div>

<div id="y" style="margin-left:100px;"></div>

...how do I find the distance between them in pixels using JavaScript?

Get their positions, and use the Pythagorean Theorem to determine the distance between them...

(function() {

    var getPositionAtCenter = function (element) {
        var data = element.getBoundingClientRect();
        return {
            x: data.left + data.width / 2,
            y: data.top + data.height / 2
        };
    };

    var getDistanceBetweenElements = function(a, b) {
        var aPosition = getPositionAtCenter(a);
        var bPosition = getPositionAtCenter(b);

        return Math.sqrt(
            Math.pow(aPosition.x - bPosition.x, 2) + 
            Math.pow(aPosition.y - bPosition.y, 2) 
        );
    };

    var distance = getDistanceBetweenElements(document.getElementById("x"),
                                              document.getElementById("y"));

})();

jsFiddle.

The Pythagorean Theorem relates to the relationship between the sides of a right-angled triangle.

The elements are plotted on a Cartesian coordinate system (with origin in top left), so you can imagine a right-angled triangle between the elements' coordinates (the unknown side is the hypotenuse).

You can modify the equation to get the value of c by getting the square root of the other side.

Then, you simply plug the values in (the x and y are the differences between the elements once their centers are determined) and you will find the length of the hypotenuse, which is the distance between the elements.