Mega Code Archive
Using firstChild and lastChild Properties
<![CDATA[
/*
JavaScript Bible, Fourth Edition
by Danny Goodman
John Wiley & Sons CopyRight 2001
*/
<HTML>
<HEAD>
<TITLE>firstChild and lastChild Properties</TITLE>
<SCRIPT LANGUAGE="JavaScript">
// helper function for prepend() and append()
function makeNewLI(txt) {
var newItem = document.createElement("LI")
newItem.innerHTML = txt
return newItem
}
function prepend(form) {
var newItem = makeNewLI(form.input.value)
var firstLI = document.getElementById("myList").firstChild
document.getElementById("myList").insertBefore(newItem, firstLI)
}
function append(form) {
var newItem = makeNewLI(form.input.value)
var lastLI = document.getElementById("myList").lastChild
document.getElementById("myList").appendChild(newItem)
}
function replaceFirst(form) {
var newItem = makeNewLI(form.input.value)
var firstLI = document.getElementById("myList").firstChild
document.getElementById("myList").replaceChild(newItem, firstLI)
}
function replaceLast(form) {
var newItem = makeNewLI(form.input.value)
var lastLI = document.getElementById("myList").lastChild
document.getElementById("myList").replaceChild(newItem, lastLI)
}
</SCRIPT>
</HEAD>
<BODY>
<H1>firstChild and lastChild Property Lab</H1>
<HR>
<FORM>
<LABEL>Enter some text to add to or replace in the OL element:</LABEL><BR>
<INPUT TYPE="text" NAME="input" SIZE=50><BR>
<INPUT TYPE="button" VALUE="Insert at Top" onClick="prepend(this.form)">
<INPUT TYPE="button" VALUE="Append to Bottom" onClick="append(this.form)">
<BR>
<INPUT TYPE="button" VALUE="Replace First Item" onClick="replaceFirst(this.form)">
<INPUT TYPE="button" VALUE="Replace Last Item" onClick="replaceLast(this.form)">
</FORM>
<P></P>
<OL ID="myList"><LI>Initial Item 1
<LI>Initial Item 2
<LI>Initial Item 3
<LI>Initial Item 4
<OL>
</BODY>
</HTML>
]]>