How do I use getElementsByTagName in Javascript?

How do I use getElementsByTagName in Javascript?

How it works:

1. First, select the button Count H2 by using the getElementById() method.
2. Second, hook the click event of the button to an anonymous function.
3. Third, in the anonymous function, use the document. getElementsByTagName() to get a list of H2 tags.
4. Finally, show the number of H2 tags using the alert() function.

What does getElementsByTagName do in Javascript?

The getElementsByTagName() method returns a collection of all elements in the document with the specified tag name, as an HTMLCollection object. The HTMLCollection object represents a collection of nodes. The nodes can be accessed by index numbers.

What is the syntax of getElementsByTagName ()?

getElementsByTagName() method returns all the element of specified tag name. The syntax of the getElementsByTagName() method is given below: document. getElementsByTagName(“name”)

How do you access the text value of the first element Say article in an XML document through DOM?

To retrieve the text value of an element, you must retrieve the value of the elements’ text node.

1. The getElementsByTagName Method.
2. The ChildNodes Property.
3. The nodeValue Property.
4. Get an Attribute Value – getAttribute()
5. Get an Attribute Value – getAttributeNode()

Can getElementsByTagName return null?

When it is defined to be null, setting it has no effect. If you want to get the text content of each node, you have to iterate over all text node descendants and concatenate their value. That said, the API implementation you are using might offer a method to directly retrieve the text content of an element.

What is the best way to parse XML in Java?

DOM Parser is the easiest java xml parser to learn. DOM parser loads the XML file into memory and we can traverse it node by node to parse the XML. DOM Parser is good for small files but when file size increases it performs slow and consumes more memory.

What is document getElementsByTagName?

getElementsByTagName() The getElementsByTagName method of Document interface returns an HTMLCollection of elements with the given tag name. The returned HTMLCollection is live, meaning that it updates itself automatically to stay in sync with the DOM tree without having to call document. …

What is the difference between getElementById and innerHTML?

getElementById() is a JavaScript selector that returns a DOM element by matching its id attribute. innerHTML points to the content of the element between its open and close tags. innerHTML is a DOM property to insert content to a specified id of an element. It is used in Javascript to manipulate DOM.

Does getElementsByTagName return an array?

getElementsByTagName – the method name itself implies that it will return multiple elements – i.e. an array.

What is a NodeList in JavaScript?

A NodeList is a collection of document nodes. A NodeList and an HTML collection is very much the same thing. Both an HTMLCollection object and a NodeList object is an array-like list (collection) of objects. Both have a length property defining the number of items in the list (collection).

What is XML parsing in Java?

XML Parser provides a way to access or modify data in an XML document. Java provides multiple options to parse XML documents. DOM4J Parser − A java library to parse XML, XPath, and XSLT using Java Collections Framework. It provides support for DOM, SAX, and JAXP.

How to use getelementsbytagname() function in JavaScript?

The getElementsByTagName () function is built in function in JavaScript. This is a function of DOM element or document object, so it is called as document.getElementsByTagName (). tagname: tagname parameter is a string parameter which specifies the tag name of an elements which we want to get.

What is the difference between getelementsbytagname and nodelist?

Definition and Usage. The getElementsByTagName() method returns a collection of all elements in the document with the specified tag name, as a NodeList object. The NodeList object represents a collection of nodes. The nodes can be accessed by index numbers. The index starts at 0. Tip: The parametervalue “*” returns all elements in the document.

What is getelementsbytagname() in Salesforce?

More “Try it Yourself” examples below. The getElementsByTagName () method returns a collection of all elements in the document with the specified tag name, as an HTMLCollection object. The HTMLCollection object represents a collection of nodes. The nodes can be accessed by index numbers. The index starts at 0.

How to get all elements in a document using HTML tags?

The getElementsByTagName () method returns a collection of all elements in the document with the specified tag name, as an HTMLCollection object. The HTMLCollection object represents a collection of nodes. The nodes can be accessed by index numbers. The index starts at 0. Tip: The parametervalue “*” returns all elements in the document.