I made this code :
function get_coordinates(container) {
var x;
var y;
var divs = container.getElementsByTagName('div');
Array.from(divs).forEach(div => {
y += div.offsetTop+" ";
x += div.offsetLeft + " ";
});
const a = x + ";" + y;
console.log(divs);
return x+";"+y;
}
this is the console log :
HTMLCollection(10) [div#selector_1.selector, div#selector_2.selector, div#selector_3.selector, div#selector_4.selector, div#selector_5.selector, div#selector_6.selector, div#selector_7.selector, div#selector_8.selector, div#selector_9.selector, div#selector_10.selector, selector_1: div#selector_1.selector, selector_2: div#selector_2.selector, selector_3: div#selector_3.selector, selector_4: div#selector_4.selector, selector_5: div#selector_5.selector, …]
and this the return :
undefined0 0 0 0 0 0 0 0 0 0 ;undefined0 0 0 0 0 0 0 0 0 0
I dont understand why i get undefined at the start of both.
As Musa advised in an earlier comment, you do not initialize x and y, so basically what you are trying to do is the following:
y += div.offsetTop + " ";
x += div.offsetLeft + " ";
That translates to
undefined += div.offsetTop + " ";
undefined += div.offsetLeft + " ";
At the top you should define that x and y are strings, for example:
let x = "";
let y = "";
Also, I would suggest using let and const instead of var, it’s 2022, so no need for var anymore.