IndexOf not Supported in IE8 Browser

Question

I have cascaded dropdown in my application, cascaded using jquery, now my problem is it is working smoothly with IE9, Firefox, Opera and Safari but does not work with any of

Answer 1

The documentation for indexOf on MDN includes a pollyfill that will add support in browsers that don't support JavaScript 1.6.

You can drop it in to avoid having to rewrite the existing code.

if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function (searchElement /*, fromIndex */ ) {
        "use strict";
        if (this == null) {
            throw new TypeError();
        }
        var t = Object(this);
        var len = t.length >>> 0;
        if (len === 0) {
            return -1;
        }
        var n = 0;
        if (arguments.length > 0) {
            n = Number(arguments[1]);
            if (n != n) { // shortcut for verifying if it's NaN
                n = 0;
            } else if (n != 0 && n != Infinity && n != -Infinity) {
                n = (n > 0 || -1) * Math.floor(Math.abs(n));
            }
        }
        if (n >= len) {
            return -1;
        }
        var k = n >= 0 ? n : Math.max(len - Math.abs(n), 0);
        for (; k < len; k++) {
            if (k in t && t[k] === searchElement) {
                return k;
            }
        }
        return -1;
    }
}

Answer 2

The indexOf() method of Arrays is not implemented in IE < 9. As you're using jQuery you can make use of the $.inArray(), e.g.

var arr = ["foo", "bar", "baz"],
    bazIndex = $.inArray("baz", arr), // 2
    doesntExistIndex = $.inArray("notThere", arr); // -1

Here's the documentation: http://api.jquery.com/jQuery.inArray/.