JS函数在FF和Safari中效果很好，但在IE9中花费很长时间

Question

Can you see any reason it would work fine in FF and Safari, but when run in IE9 it completely craps out? It takes forever and almost hangs the browser. Thanks!

This is a function that refreshes a list after a keypress. The function clears the list, and then does a linear search through the globally defined array and adds the matches back to the list.

function handleKeyUp()
{
    var selectObj, textObj, componentListLength;
    var i, searchPattern, numShown;

    // Set references to the form elements
    selectObj = document.form1.componentselect;
    textObj = document.form1.componentinput;

    // Remember the function list length for loop speedup
    componentListLength = componentlist.length;

    // Set the search pattern depending
    if(document.form1.componentradio[0].checked == true)
    {
        searchPattern = "^"+textObj.value;
    }
    else
    {
        searchPattern = textObj.value;
    }

    // Create a regular expression
    re = new RegExp(searchPattern,"gi");
    // Clear the options list
    selectObj.length = 0;

    // Loop through the array and re-add matching options
    numShown = 0;
    for(i = 0; i < componentListLength; i++)
    {
        if(componentlist[i].search(re) != -1)
        {
            selectObj[numShown] = new Option(componentlist[i],"");
            numShown++;
        }
    }
}

Answer 1

Two things that look fishy to me:

// Clear the options list
selectObj.length = 0;
// should be
selectObj.options.length = 0;


// Next thing, adding them back
selectObj[numShown] = new Option(componentlist[i],"");
// should be
selectObj.options[numShown] = new Option(componentlist[i],"");