HTML DOM length Property
Element ObjectExample
Find out how many <p> elements there are in the document:
var nodelist = document.getElementsByTagName("P").length;
The result of nodelist will be:
4
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More "Try it Yourself" examples below.
Definition and Usage
The length property returns the number of nodes in a NodeList object.
A Node object's collection of child nodes is an example of a NodeList object.
The length property is useful when you want to loop through the nodes in a node list (See "More Examples" below).
This property is read-only.
Tip: Use the item() method to return a node at the specified index in a NodeList object.
Browser Support
| Property | |||||
|---|---|---|---|---|---|
| length | Yes | Yes | Yes | Yes | Yes |
Syntax
nodelist.length
Technical Details
| Return Value: | A Number, representing the number of nodes in the nodelist |
|---|---|
| DOM Version | Core Level 1 Nodelist Object |
More Examples
Example
Find out how many <p> elements there are inside a <div> element:
var div = document.getElementById("myDIV");
// Get the <div> element with id="myDIV"
var nodelist = div.getElementsByTagName("P").length; // Get the number of <p> elements inside <div>
The result of nodelist will be:
3
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Example
Loop through all <p> elements inside a <div> element, and change the background color of each <p>:
var div = document.getElementById("myDIV");
var nodelist =
div.getElementsByTagName("P");
var i;
for (i = 0; i <
nodelist.length; i++) {
nodelist[i].style.backgroundColor = "red";
}
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Example
Return the number of child nodes of the <body> element:
var nodelist = document.body.childNodes.length;
The result of nodelist will be:
12
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Example
Loop through the child nodes of <body> and output the node name of each child node:
var nodelist = document.body.childNodes;
var txt = "";
var i;
for (i = 0;
i < nodelist.length; i++) {
txt = txt +
nodelist[i].nodeName + "<br>";
}
The result of txt will be:
#comment
#text
P
#text
BUTTON
#text
P
#text
P
#text
SCRIPT
#text
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Related Pages
HTML DOM Reference: nodelist.item() Method
HTML DOM Reference: element.childNodes Property
HTML DOM Reference: element.getElementsByClassName() Method
HTML DOM Reference: element.getElementsByTagName() Method
HTML DOM Reference: element.querySelectorAll() Method
HTML DOM Reference: document.getElementsByClassName() Method
HTML DOM Reference: document.getElementsByName() Method
HTML DOM Reference: document.getElementsByTagName() Method
HTML DOM Reference: document.querySelectorAll() Method
