How to fix this error "Uncaught DOMException: Failed to execute 'querySelectorAll' on 'Document': 'div.com[min=]' is not a valid selector"? [duplicate]

Question

I am trying to hide the comments with the children like reddit, and I wrote this function:

function toggle(id, lft, rgt) {
    var kids = (rgt - lft - 1) / 2;
    if (kids >= 1) {
        var element = document.querySelector("div.com#com" + id).getAttribute('value');
        var low = Number(element.split('-')[0]);
        var high = Number(element.split('-')[1]);
        for (var i = low + 1; i <= high - 1; i += 1) {
            const x = document.querySelectorAll('div.com[min=' + i + ']');
        }
        Array.from(x).forEach(comment => {
            if (comment.style.display === "none") {
                comment.style.display = "block";
            } else {
                comment.style.display = "none";
            }
        });
    }

for example this is the parent comment:

<div> 
      <a onclick="return toggle(1, 1, 4)" href="javascript:void(0)">[-]</a>
       <div id="com1" class="com md" value="1-4" min="1">yellow</div>
</div> 

and this is a child comment:

<div> 
     <a onclick="return toggle(2, 2, 3)" href="javascript:void(0)">[-]</a>
    <div id="com2" class="com md" value="2-3" min="2">hello </div>
</div> 

I want to hide all the comments that have the min attribute between the parent value 1 and 4 and this child have the min=2 so it must be hidden. BUT the js function isn't working, so what's the problem?

other questions?

• Should I write the foreach inside the for loop or it's fine like this way?
• if the error in the title is fixed, will the function work and the child comments will be hidden, if not, why?

Answer 1

Well, as the error message says, your selector is invalid. Add quotation marks around the value of the attribute.

const x = document.querySelectorAll(`div.com[min="${i}"]`);

(It looks more readable with ES6 template literals).