.indexOf function on an array not working in IE7/8 using JavaScript

arrays, function, internet-explorer-7, internet-explorer-8, javascript

Solution

On IE<9 `indexOf()` it is not "well" implemented. Try to add this function on your code :

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

It will "replace" the original function, if not found in the ECMA-262 standard.

Problem

Can anyone tell me if IE 7 and IE 8 support the JavaScript .indexOf() method as I am receiving the error: ``` SCRIPT438: Object doesn't support property or method 'indexOf' ``` from the IE9 debug console (used under both IE7 and IE8 Browser mode). For the below comment, the code using .indexOf() is as follows: ``` if(shirt_colour == 'black') { p_arr=['orange','red','green','yellow','bblue','rblue','pink','white','silver','gold']; if( p_arr.indexOf(print_colour) != -1 ) rtn = true; } ```

Original source