Beispiele für die Verwendung von JavaScript für den Zugriff auf und die Bearbeitung von DOM-Objekten.
Alle Name/Wert-Paare von Cookies in einem Dokument anzeigen
<!DOCTYPE html>
<html>
<body>
<p id="demo">Click the button to display the cookies associated with this document.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.getElementById("demo").innerHTML =
"Cookies associated with this document: " + document.cookie;
}
</script>
</body>
</html>
Zeigt den Domänennamen des Servers an, der das Dokument geladen hat
<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the domain name of the server that loaded this document.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML = document.domain;
}
</script>
</body>
</html>
Zeigt das Datum und die Uhrzeit der letzten Änderung des Dokuments an
<!DOCTYPE html>
<html>
<body>
<p>This document was last modified <span id="demo"></span>.</p>
<script>
document.getElementById("demo").innerHTML = document.lastModified;
</script>
</body>
</html>
Zeigt die URL des Dokuments an, das das aktuelle Dokument geladen hat
<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the referrer of this document.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML = document.referrer;
}
</script>
</body>
</html>
Zeigt den Titel eines Dokuments an
<!DOCTYPE html>
<html>
<head>
<title>W3Schools Demo</title>
</head>
<body>
<h2>Finding HTML Elements Using document.title</h2>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"The title of this document is: " + document.title;
</script>
</body>
</html>
Zeigt die vollständige URL eines Dokuments an
<!DOCTYPE html>
<html>
<body>
<p>The full URL of this document is: <br><span id="demo"></span>.</p>
<script>
document.getElementById("demo").innerHTML = document.URL
</script>
</body>
</html>
Ersetzen Sie den Inhalt eines Dokuments
<!DOCTYPE html>
<html>
<body>
<p id="demo">Click the button to replace this document with new content.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.open("text/html","replace");
document.write("<h2>Learning about the HTML DOM is fun!</h2>");
document.close();
}
</script>
</body>
</html>
Öffnen Sie ein neues Fenster und fügen Sie Inhalte hinzu
<!DOCTYPE html>
<html>
<body>
<p>Click the button to open a new window and add some content.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var w = window.open();
w.document.open();
w.document.write("<h2>Hello World!</h2>");
w.document.close();
}
</script>
</body>
</html>
Zeigt die Anzahl der Elemente mit einem bestimmten Namen an
<!DOCTYPE html>
<html>
<head>
<script>
function getElements() {
var x = document.getElementsByName("x");
document.getElementById("demo").innerHTML = x.length;
}
</script>
</head>
<body>
<p>
Cats: <input name="x" type="radio" value="Cats">
Dogs: <input name="x" type="radio" value="Dogs">
</p>
<p>
<input type="button" onclick="getElements()" value="How many elements named x?">
</p>
<p id="demo"></p>
</body>
</html>
Zeigt die Anzahl der Elemente mit einem bestimmten Tag-Namen an
<!DOCTYPE html>
<html>
<head>
<script>
function getElements() {
var x = document.getElementsByTagName("input");
document.getElementById("demo").innerHTML = x.length;
}
</script>
</head>
<body>
<input type="text" size="20"><br>
<input type="text" size="20"><br>
<input type="text" size="20"><br>
<p>
<input type="button" onclick="getElements()" value="How many input elements?">
</p>
<p id="demo"></p>
</body>
</html>
Dokumentobjekt erklärt
Ermitteln Sie die Anzahl der Anker in einem Dokument
<!DOCTYPE html>
<html>
<body>
<h2>Finding HTML Elements Using document.anchors</h2>
<a name="html">HTML Tutorial</a><br>
<a name="css">CSS Tutorial</a><br>
<a name="xml">XML Tutorial</a><br>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"Number of anchors are: " + document.anchors.length;
</script>
</body>
</html>
Suchen Sie das innerHTML des ersten Ankers in einem Dokument
<!DOCTYPE html>
<html>
<body>
<a name="html">HTML Tutorial</a><br>
<a name="css">CSS Tutorial</a><br>
<a name="xml">XML Tutorial</a><br>
<p>Click the button to display the innerHTML of the first anchor in the document.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML =
document.anchors[0].innerHTML;
}
</script>
</body>
</html>
Zeigt die Anzahl der Links in einem Dokument an
<!DOCTYPE html>
<html>
<body>
<h2>Finding HTML Elements Using document.links</h2>
<p>
<a href="/html/default.asp">HTML</a>
<br>
<a href="/css/default.asp">CSS</a>
</p>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"Number of links: " + document.links.length;
</script>
</body>
</html>
Zeigt das href-Attribut des ersten Links in einem Dokument an
<!DOCTYPE html>
<html>
<body>
<p>
<a href="/html/default.asp">HTML</a>
<br>
<a href="/css/default.asp">CSS</a>
</p>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"The href of the first link is " + document.links[0].href;
</script>
</body>
</html>
Finden Sie die Anzahl der Formulare in einem Dokument
<!DOCTYPE html>
<html>
<body>
<h2>Finding HTML Elements Using document.forms</h2>
<form action="">
First name: <input type="text" name="fname" value="Donald">
<input type="submit" value="Submit">
</form>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"Number of forms: " + document.forms.length;
</script>
</body>
</html>
Suchen Sie den Namen des ersten Formulars in einem Dokument
<!DOCTYPE html>
<html>
<body>
<form name="Form1"></form>
<form name="Form2"></form>
<form name="Form3"></form>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"The name of the first for is " + document.forms[0].name;
</script>
</body>
</html>
Gibt die Anzahl der Bilder in einem Dokument zurück
<!DOCTYPE html>
<html>
<body>
<h2>Finding HTML Elements Using document.images</h2>
<img src="pic_htmltree.gif" width="486" height="266">
<img src="pic_navigate.gif" width="362" height="255">
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"Number of images: " + document.images.length;
</script>
</body>
</html>
Gibt die ID des ersten Bildes in einem Dokument zurück
<!DOCTYPE html>
<html>
<body>
<img id="img1" src="pic_htmltree.gif">
<img id="img2" src="pic_navigate.gif">
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML =
"The id of the first image is " + document.images[0].id;
</script>
</body>
</html>
Ändern Sie die Sichtbarkeit eines HTML-Elements
<!DOCTYPE html>
<html>
<body>
<p id="p1">
This is a text.
This is a text.
This is a text.
</p>
<input type="button" value="Hide text"
onclick="document.getElementById('p1').style.visibility='hidden'">
<input type="button" value="Show text"
onclick="document.getElementById('p1').style.visibility='visible'">
</body>
</html>
Ändern Sie die Hintergrundfarbe eines HTML-Elements
<!DOCTYPE html>
<html>
<head>
<script>
function bgChange(bg) {
document.body.style.background = bg;
}
</script>
</head>
<body>
<h2>Change background color</h2>
<p>Mouse over the squares!</p>
<table style="width:300px;height:100px">
<tr>
<td onmouseover="bgChange(this.style.backgroundColor)"
onmouseout="bgChange('transparent')"
style="background-color:Khaki">
</td>
<td onmouseover="bgChange(this.style.backgroundColor)"
onmouseout="bgChange('transparent')"
style="background-color:PaleGreen">
</td>
<td onmouseover="bgChange(this.style.backgroundColor)"
onmouseout="bgChange('transparent')"
style="background-color:Silver">
</td>
</tr>
</table>
</body>
</html>