Javascript 中的给定值除以.style.width

Question

I would need to divide a value given by.style.width function in Javascript. My code looks like this:

    var x = document.getElementsByClassName("item");
    var i;

    var v = x[0].style.width; 

In variable 'v' I have some value in pixels, eg 200px width. I would need to divide this value by 2 to get 100px. But this formula doesn't work: var v = x[0].style.width / 2;

What am I doing wrong? Thanks for help.

Answer 1

width will be string. Convert it to number before dividing. This example uses getComputedStyle to get actual width of a dom element

 let elem = document.getElementById('test'); let compStyles = window.getComputedStyle(elem); const widthInteger = parseInt(compStyles.width, 10); const halfWidth = widthInteger / 2; console.log(halfWidth)

 .test { height: 200px; width: 200px; border: 1px solid green; }

 <div class='test' id='test'></div>