调用事件处理程序似乎不起作用

Question

I have this code for collapsible items.

var coll = document.getElementsByClassName("collapsible");

for (var i = 0; i < coll.length; i++) {
    coll[i].addEventListener("click", function() {        
        this.classList.toggle("active");
        var p = this.nextElementSibling;
        if (p.style.maxHeight){
            p.style.maxHeight = null;
        } else {
            p.style.maxHeight = p.scrollHeight + "px";
        } 
    });
    if (window.screen.availWidth >= 768) coll[i].onclick.apply(coll[i]);
}

The last line is meant to automatically expand all collapsibles on larger screens. But it gives me an error:

Uncaught TypeError: Cannot read property 'apply' of null

How can I fix this?

Answer 1

coll[i].onclick is null, onclick is an event not a function, so you would like to use click function there.

Not sure what are you trying to achieve by passing coll[i] as this for click function. but try:

coll[i].click.apply()

or simpler:

coll[i].click()