
JavaScript
HTML DOM Node List
A node list
is a collection of nodes
HTML DOM
Node List
The
getElementsByTagName() method returns a node list. A node list is an array-like
collection of nodes.
The
following code selects all <p> nodes in a document:
Example
var
x = document.getElementsByTagName("p");
The nodes
can be accessed by an index number. To access the second <p> node you can
write:
y
= x[1];
»
Note:
The index starts at 0.
HTML
DOM Node List Length
The
length property defines the number of nodes in a node list:
Example
var
myNodelist = document.getElementsByTagName("p");
document.getElementById("demo").innerHTML
= myNodelist.length;
»
Example
explained:
Get all
<p> elements in a node list
Display the
length of the node list
The length
property is useful when you want to loop through the nodes in a node list:
Example
Change
the background color of all <p> elements in a node list:
var
myNodelist = document.getElementsByTagName("p");
var
i;
for
(i = 0; i < myNodelist.length; i++) {
myNodelist[i].style.backgroundColor =
"red";
}
»
A node list
is not an array!
A node list
may look like an array, but it is not. You can loop through the node list and
refer to its nodes like an array. However, you cannot use Array Methods, like
valueOf() or join() on the node list.
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