IE8返回“对象预期”原型

Question

I have this code, that works good on all browser and IE9> , but in IE8 it throws me JScript Object Expected on the first line ( Array.prototype... )

this.items = Array.prototype.slice.call( document.querySelectorAll( '#' + this.el.id + ' > li' ) );
            this.itemsCount = this.items.length;
            this.itemsRenderedCount = 0;
            this.didScroll = false;

I tried changing document.querySelectorAll( '#' + this.el.id + ' > li' ) to $(this).attr("id") - same error.

But when i change this line to simple jquery picker , for example $("#someId") , it works fine.

Ideas anyone?

Answer 1

This is because IE8 and lower requires a native object as the this value of built-in Array methods. The collection you're passing is a host object.

You need to do the conversion manually instead.

Here's a simple example:

function _slice(arr) {
    try {   // try using .slice()
        return Array.prototype.slice.call(arr);
    } catch(e) {
            // otherwise, manually create the array
        var result = [];
        for (var i = 0; i < arr.length; ++i)
            result.push(arr[i]);
        return result;
    }
}

---

this.items = _slice( document.querySelectorAll( '#' + this.el.id + ' > li' ) );

---

Side note, since this.el must be a ul or ol element, and so its children must be li elements, why not just do this?

this.items = _slice( this.el.children );