JavaScript EditorFree JavaScript Editor     DHTML Editor 

Main Page Previous Section Next Section

14.15 Removing Body Content

NN 6, IE 5

14.15.1 Problem

You want to eliminate an element or portion of text from the current document.

14.15.2 Solution

If you have a reference to the element you wish to delete, you can use the W3C DOM removeChild( ) method to remove the element. The method works only on child nodes, so you must step outward to the element's parent to invoke the method:

var elem = document.getElementById("spanToGo");

To eliminate text from a text node, set its node value to an empty string:

var container = document.getElementById("someSpan");
// verify that the child node is a text node before emptying it
if (container.firstChild.nodeType =  = 3) {
    container.firstChild.nodeValue = "";

To remove the text node entirely, use the removeChild( ) method as shown above for the element node removal.

14.15.3 Discussion

When you remove repetitive elements, such as rows of a table, you may need to iterate through a collection when appropriate. For example, a table or tbody element object has a rows property that returns a collection of all tr element objects nested within. If you intend to remove all the rows, it is more efficient to remove them via a tight while loop, acting on the first child until there are no more children:

var tbody = document.getElementById("myTableBody");
while (tbody.rows.length > 0) {

But if removal among a collection is meant to be selective, you also have to account for a changing collection of numeric indexes for the collection's array while the array gets smaller. To work around this potential problem, use a for loop that starts at the end and decrements the index counter so that the counter doesn't get off track with a changing collection.

For an example of selective deletion in action, consider the following table, in which each row contains a checkbox and some text. A button at the bottom of the table deletes any and all rows in which the checkbox is checked. The HTML for the table is as follows:

<tbody id="myTBody">
    <td><input type="checkbox"></td><td>Item 1</td>
    <td><input type="checkbox"></td><td>Item 2</td>
    <td><input type="checkbox"></td><td>Item 3</td>
    <td><input type="checkbox"></td><td>Item 4</td>
    <td><input type="checkbox"></td><td>Item 5</td>
    <td colspan="2">
    <input type="button" value="Remove Checked" onclick="remove( )"></td>

The remove( ) function is as follows:

function remove( ) {
    var elem = document.getElementById("myTBody");
    for (var i = elem.rows.length-1; i >= 0 ; i--) {
        if (elem.rows[i].cells[0].firstChild.checked) {

You could also use the deleteRow( ) method of the tbody object in the function.

14.15.4 See Also

Recipe 14.13 for ways to reference elements in the document.

    Main Page Previous Section Next Section

    JavaScript EditorJavaScript Checker     DHTML Editor