The DOM forms collection is used to return the collection of all <form> elements in a HTML document. The form elements are sorted as they appear in the source code.
Syntax:
document.forms
Properties: It returns the number of form in the collection of elements.
Methods: The DOM forms collection contains three methods which are listed below:
- [index]: It is used to return the <form> element of the specified index. The index value starts at 0. NULL is returned if the index value is out of range.
- item(index): It is used to return the <form> element of specified index. The index value starts at 0. NULL is returned if the index value is out of range. This method performs similarly to the above method.
- namedItem(id): It is used to return the <form> element from the collection which matches the specified id. NULL is returned if the id does not exist.
Below programs illustrate the use of the documents.forms property in HTML:
Example 1: This example use length property to count number of form elements in the collection.
html
<!DOCTYPE html>
<html>
<head>
<title>
HTML | DOM forms Collection
</title>
</head>
<body>
<h1 style = "color:green">GeeksForGeeks</h1>
<h2>DOM document.forms Property</h2>
<form id="personal-info">
<h3>Personal Information Area</h3>
Name: <input type="text">
</form>
<form id="home-info">
<h3>Home Address Information Area</h3>
Address: <input type="text">
</form>
<form id="delivery-info">
<h3>Delivery Type Area</h3>
Delivery Speed: <input type="text">
</form>
<p>
Click the button below to count
the number of forms:
</p>
<button onclick = "countForms()">
Count forms
</button>
<p>
The total number of forms in
this page is:
</p>
<div class = "count"></div>
<script>
function countForms() {
// Count number of forms
let collection = document.forms.length;
document.querySelector(".count").innerHTML
= collection;
}
</script>
</body>
</html>
|
Output:
Before Click on the button:
After Click on the button:
Example 2:
html
<!DOCTYPE html>
<html>
<head>
<title>
HTML | DOM forms Collection
</title>
</head>
<body>
<h1 style="color:green">GeeksForGeeks</h1>
<h2>DOM document.forms Property</h2>
<form id = "personal-info">
<h3>Personal Information Area</h3>
Name: <input type="text">
</form>
<form id="home-info">
<h3>Home Address Information Area</h3>
Address: <input type="text">
</form>
<form id="delivery-info">
<h3>Delivery Type Area</h3>
Delivery Speed: <input type="text">
</form>
<p>
Click the button below to find
all form IDs:
</p>
<button onclick="findFormIDs()">
Find form IDs
</button>
<p>The ID of all the forms is: </p>
<div class = "ids"></div>
<script>
function findFormIDs() {
let final = '';
let collection = document.forms;
// Run a loop upto the number of
// forms in the collection
for (let i = 0; i < collection.length; i++) {
// Add each form id to the final list
final += `<li> ${collection[i].id} </li>`;
}
// Replace the inner HTML of the
// ID div to show the list
document.querySelector(".ids").innerHTML = final;
}
</script>
</body>
</html>
|
Output:
Before Click on the button:
After Click on the button:
Example 3:
html
<!DOCTYPE html>
<html>
<head>
<title>HTML | DOM forms Collection
</title>
</head>
<body>
<h1 style="color:green">GeeksForGeeks</h1>
<h2>DOM document.forms Property</h2>
<form id="personal-info">
<h3>Personal Information Area</h3>
Name: <input type="text">
</form>
<form id="home-info">
<h3>Home Address Information Area</h3>
Address: <input type="text">
</form>
<form id="delivery-info">
<h3>Delivery Type Area</h3>
Delivery Speed: <input type="text">
</form>
<p>
Click the button below to find by form
ID and get the name field:
</p>
<button onclick="returnForm()">
Find by form ID
</button>
<p>The text in the name field is: </p>
<div class="name"></div>
<script>
function returnForm() {
// find by id of 'personal-info'
let collection =
document.forms.namedItem("personal-info");
// access the first element in the
//collection and find its value
// in this case it would be the name field
let name = collection[0].value;
document.querySelector(".name").innerHTML = name;
}
</script>
</body>
</html>
|
Output:
Before Click on the button:
After Click on the button:
Supported Browsers: The browser supported by DOM forms collection method are listed below:
- Google Chrome 1 and above
- Edge 12 and above
- Internet Explorer 4 and above
- Firefox 1 and above
- Safari 1 and above
- Opera 12.1 and above