What is CSS?
Cascading
Style Sheets (CSS) is used to format the layout of a webpage.
With
CSS, you can control the color, font, the size of text, the spacing between
elements, how elements are positioned and laid out, what background images or
background colors are to be used, different displays for different devices and
screen sizes, and much more!
Using CSS
CSS can be added to HTML documents in 3 ways:
- Inline - by
using the
style attribute inside HTML elements
- Internal - by
using a
<style> element in the <head> section
- External - by
using a
<link> element to link to an external
CSS file
The most common way to add CSS, is to keep the styles in external
CSS files. However, in this tutorial we will use inline and internal styles,
because this is easier to demonstrate, and easier for you to try it yourself.
Inline CSS
An inline CSS is used to apply a unique style to a single HTML
element.
An inline CSS uses the style attribute
of an HTML element.
The following example sets the text color of the <h1> element
to blue, and the text color of the <p> element
to red:
Example
<h1 style="color:blue;">A Blue Heading</h1>
<p style="color:red;">A red paragraph.</p>
Internal CSS
An internal CSS is used to define a style for a single HTML page.
An internal CSS is defined in the <head> section
of an HTML page, within a <style> element.
The following example sets the text color of ALL the <h1> elements
(on that page) to blue, and the text color of ALL the <p> elements
to red. In addition, the page will be displayed with a "powderblue"
background color:
Example
<!DOCTYPE html>
<html>
<head>
<style>
body {background-color: powderblue;}
h1 {color: blue;}
p {color: red;}
</style>
</head>
<body>
<h1>This
is a heading</h1>
<p>This
is a paragraph.</p>
</body>
</html>
External CSS
An external style sheet is used to define the style for many HTML
pages.
To use an external style sheet, add a link to it in the <head> section
of each HTML page:
Example
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<h1>This
is a heading</h1>
<p>This
is a paragraph.</p>
</body>
</html>
The external style sheet can be written in any text editor. The
file must not contain any HTML code, and must be saved with a .css extension.
Here is what the "styles.css" file looks like:
"styles.css":
body {
background-color: powderblue;
}
h1 {
color: blue;
}
p {
color: red;
}
Tip: With an external style sheet, you can
change the look of an entire web site, by changing one file!
CSS Colors, Fonts and Sizes
Here, we will demonstrate some commonly used CSS properties. You
will learn more about them later.
The CSS color property defines
the text color to be used.
The CSS font-family property
defines the font to be used.
The CSS font-size property
defines the text size to be used.
Example
Use of CSS color, font-family and font-size properties:
<!DOCTYPE html>
<html>
<head>
<style>
h1 {
color: blue;
font-family: verdana;
font-size: 300%;
}
p {
color: red;
font-family: courier;
font-size: 160%;
}
</style>
</head>
<body>
<h1>This
is a heading</h1>
<p>This
is a paragraph.</p>
</body>
</html>
CSS Border
The CSS border property defines a
border around an HTML element.
Tip: You can define a border for nearly
all HTML elements.
Example
Use of CSS border property:
p {
border: 2px solid powderblue;
}
CSS Padding
The CSS padding property
defines a padding (space) between the text and the border.
Example
Use of CSS border and padding properties:
p {
border: 2px solid powderblue;
padding: 30px;
}
CSS Margin
The CSS margin property defines a
margin (space) outside the border.
Example
Use of CSS border and margin properties:
p {
border: 2px solid powderblue;
margin: 50px;
}
Link to External CSS
External style sheets can be referenced with a full URL or with a
path relative to the current web page.
Example
This example uses a full URL to link to a style sheet:
<link rel="stylesheet" href="https://www.w3schools.com/html/styles.css">
Example
This example links to a style sheet located in the html folder on
the current web site:
<link rel="stylesheet" href="/html/styles.css">
Example
This example links to a style sheet located in the same folder as
the current page:
<link rel="stylesheet" href="styles.css">
HTML - Forms
HTML Forms are required,
when you want to collect some data from the site visitor. For example, during
user registration you would like to collect information such as name, email
address, credit card, etc.
A form will take input from
the site visitor and then will post it to a back-end application such as CGI,
ASP Script or PHP script etc. The back-end application will perform required
processing on the passed data based on defined business logic inside the
application.
There are various form
elements available like text fields, textarea fields, drop-down menus, radio
buttons, checkboxes, etc.
The HTML <form> tag
is used to create an HTML form and it has following syntax −
<form action = "Script URL" method =
"GET|POST">
form elements
like input, textarea etc.
</form>
HTML Form Controls
There are different types
of form controls that you can use to collect data using HTML form −
- Text Input Controls
- Checkboxes Controls
- Radio Box Controls
- Select Box Controls
- File Select boxes
- Hidden Controls
- Clickable Buttons
- Submit and Reset Button
Text Input Controls
There are three types of text input used on forms −
·
Single-line text input controls − This control is used for items that
require only one line of user input, such as search boxes or names. They are
created using HTML <input> tag.
·
Password input controls − This is also a single-line text input but it masks the
character as soon as a user enters it. They are also created using HTMl
<input> tag.
·
Multi-line text input controls − This is used when the user is
required to give details that may be longer than a single sentence. Multi-line
input controls are created using HTML <textarea> tag.
Single-line text input controls
This control is used for items that require only one line of user
input, such as search boxes or names. They are created using HTML <input>
tag.
Example
Here is a basic example of a single-line text input used to take
first name and last name −
<!DOCTYPE html>
<html>
<head>
<title>Text Input Control</title>
</head>
<body>
<form >
First name: <input type = "text" name = "first_name" />
<br>
Last name: <input type = "text" name = "last_name" />
</form>
</body>
</html>
|
Sr.No
|
Attribute
& Description
|
|
1
|
type
Indicates the type of
input control and for text input control it will be set to text.
|
|
2
|
name
Used to give a name to
the control which is sent to the server to be recognized and get the value.
|
|
3
|
value
This can be used to
provide an initial value inside the control.
|
|
4
|
size
Allows to specify the
width of the text-input control in terms of characters.
|
|
5
|
maxlength
Allows to specify the
maximum number of characters a user can enter into the text box.
|
Password input controls
This is also a single-line text input but it masks the character
as soon as a user enters it. They are also created using HTML <input>tag
but type attribute is set to password.
Example
Here is a basic example of a single-line password input used to
take user password –
<!DOCTYPE html>
<html>
<head>
<title>Password Input Control</title>
</head>
<body>
<form >
User ID : <input type = "text" name = "user_id" />
<br>
Password: <input type = "password" name = "password" />
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of attributes for <input> tag for
creating password field.
|
Sr.No
|
Attribute & Description
|
|
1
|
type
Indicates the type of input control and for password input
control it will be set to password.
|
|
2
|
name
Used to give a name to the control which is sent to the server
to be recognized and get the value.
|
|
3
|
value
This can be used to provide an initial value inside the control.
|
|
4
|
size
Allows to specify the width of the text-input control in terms
of characters.
|
|
5
|
maxlength
Allows to specify the maximum number of characters a user can
enter into the text box.
|
Multiple-Line Text Input Controls
This is used when the user is required to give details that may be
longer than a single sentence. Multi-line input controls are created using HTML
<textarea> tag.
Example
Here is a basic example of a multi-line text input used to take
item description −
<!DOCTYPE html>
<html>
<head>
<title>Multiple-Line Input Control</title>
</head>
<body>
<form>
Description : <br />
<textarea rows = "5" cols = "50" name = "description">
Enter description here...
</textarea>
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of attributes for <textarea> tag.
|
Sr.No
|
Attribute & Description
|
|
1
|
name
Used to give a name to the control which is sent to the server
to be recognized and get the value.
|
|
2
|
rows
Indicates the number of rows of text area box.
|
|
3
|
cols
Indicates the number of columns of text area box
|
Checkbox Control
Checkboxes are used when more than one option is required to be
selected. They are also created using HTML <input> tag but type attribute
is set to checkbox..
Example
Here is an example HTML code for a form with two checkboxes −
Live Demo
<!DOCTYPE html>
<html>
<head>
<title>Checkbox Control</title>
</head>
<body>
<form>
<input type = "checkbox" name = "maths" value = "on"> Maths
<input type = "checkbox" name = "physics" value = "on"> Physics
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of attributes for <checkbox> tag.
|
Sr.No
|
Attribute & Description
|
|
1
|
type
Indicates the type of input control and for checkbox input
control it will be set to checkbox..
|
|
2
|
name
Used to give a name to the control which is sent to the server
to be recognized and get the value.
|
|
3
|
value
The value that will be used if the checkbox is selected.
|
|
4
|
checked
Set to checked if you want to select it by
default.
|
Radio Button Control
Radio buttons are used when out of many options, just one option
is required to be selected. They are also created using HTML <input> tag
but type attribute is set to radio.
Example
Here is example HTML code for a form with two radio buttons −
Live Demo
<!DOCTYPE html>
<html>
<head>
<title>Radio Box Control</title>
</head>
<body>
<form>
<input type = "radio" name = "subject" value = "maths"> Maths
<input type = "radio" name = "subject" value = "physics"> Physics
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of attributes for radio button.
|
Sr.No
|
Attribute & Description
|
|
1
|
type
Indicates the type of input control and for checkbox input
control it will be set to radio.
|
|
2
|
name
Used to give a name to the control which is sent to the server
to be recognized and get the value.
|
|
3
|
value
The value that will be used if the radio box is selected.
|
|
4
|
checked
Set to checked if you want to select it by
default.
|
Select Box Control
A select box, also called drop down box which provides option to
list down various options in the form of drop down list, from where a user can
select one or more options.
Example
Here is example HTML code for a form with one drop down box
Live Demo
<!DOCTYPE html>
<html>
<head>
<title>Select Box Control</title>
</head>
<body>
<form>
<select name = "dropdown">
<option value = "Maths" selected>Maths</option>
<option value = "Physics">Physics</option>
</select>
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of important attributes of <select>
tag −
|
Sr.No
|
Attribute & Description
|
|
1
|
name
Used to give a name to the control which is sent to the server
to be recognized and get the value.
|
|
2
|
size
This can be used to present a scrolling list box.
|
|
3
|
multiple
If set to "multiple" then allows a user to select
multiple items from the menu.
|
Following is the list of important attributes of <option>
tag −
|
Sr.No
|
Attribute & Description
|
|
1
|
value
The value that will be used if an option in the select box box
is selected.
|
|
2
|
selected
Specifies that this option should be the initially selected
value when the page loads.
|
|
3
|
label
An alternative way of labeling options
|
File Upload Box
If you want to allow a user to upload a file to your web site, you
will need to use a file upload box, also known as a file select box. This is
also created using the <input> element but type attribute is set to file.
Example
Here is example HTML code for a form with one file upload box −
Live Demo
<!DOCTYPE html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<input type = "file" name = "fileupload" accept = "image/*" />
</form>
</body>
</html>
This will produce the following result −
Attributes
Following is the list of important attributes of file upload box −
|
Sr.No
|
Attribute & Description
|
|
1
|
name
Used to give a name to the control which is sent to the server to
be recognized and get the value.
|
|
2
|
accept
Specifies the types of files that the server accepts.
|
Button Controls
There are various ways in HTML to create clickable buttons. You
can also create a clickable button using <input>tag by setting its type attribute
to button. The type attribute can take the following values −
|
Sr.No
|
Type & Description
|
|
1
|
submit
This creates a button that automatically submits a form.
|
|
2
|
reset
This creates a button that automatically resets form controls to
their initial values.
|
|
3
|
button
This creates a button that is used to trigger a client-side
script when the user clicks that button.
|
|
4
|
image
This creates a clickable button but we can use an image as
background of the button.
|
Example
Here is example HTML code for a form with three types of buttons −
Live Demo
<!DOCTYPE html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<input type = "submit" name = "submit" value = "Submit" />
<input type = "reset" name = "reset" value = "Reset" />
<input type = "button" name = "ok" value = "OK" />
<input type = "image" name = "imagebutton" src = "/html/images/logo.png" />
</form>
</body>
</html>
This will produce the following result −
Hidden Form Controls
Hidden form controls are used to hide data inside the page which
later on can be pushed to the server. This control hides inside the code and
does not appear on the actual page. For example, following hidden form is being
used to keep current page number. When a user will click next page then the
value of hidden control will be sent to the web server and there it will decide
which page will be displayed next based on the passed current page.
Example
Here is example HTML code to show the usage of hidden control −
<!DOCTYPE html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<p>This is page 10</p>
<input type = "hidden" name = "pagename" value = "10" />
<input type = "submit" name = "submit" value = "Submit" />
<input type = "reset" name = "reset" value = "Reset" />
</form>
</body>
</html>
