Question

i have a div, div1 with a height according to the text, div2 is the same. Now i need div3 to be: div1 + div2

I have this code, but it ain’t workin.

var lengthnews1 = ((document.getElementById("div1").offsetHeight)+"px");
var lengthnews2 = ((document.getElementById("div2").offsetHeight)+"px");
var x = document.getElementById("div3");
x.height = (lengthnews1 + lengthnews2); 

Answer 1

you are trying to add two strings, not numbers. Fetch both heights, add them and then add the “px” :

var lengthnews1 = ((document.getElementById("div1").offsetHeight));
var lengthnews2 = ((document.getElementById("div2").offsetHeight));

var x = document.getElementById("div3");
x.height = (lengthnews1 + lengthnews2) + "px"; 

You can verify the working code at this fiddle