April 11, 2010, 9:56 am
The id and class Selectors
In addition to setting a style for a HTML element, CSS allows you to specify your own selectors called “id” and “class”.
The id Selector
The id selector is used to specify a style for a single, unique element.
The id selector uses the id attribute of the HTML element, and is defined with a “#”.
The style rule below will be applied to the element with id=”para1″:
Example
#para1
{
text-align:center;
color:red;
} |
|
Do NOTstart an ID name with a number! It will not work in Mozilla/Firefox. Continue reading ‘CSS Id and Class’ »
March 28, 2010, 8:12 am
Class is a group of 1) instances of the same element to which an unique style can be attached or 2) instances of different elements to which the same style can be attached.
1) The rule P {color: red} will display red text in all paragraphs. By classifying the selector P different style can be attached to each class allowing the display of some paragraphs in one style and some other paragraphs in another style.
2) A class can also be specified without associating a specific element to it and then attached to any element which is to be styled in accordance with it’s declaration. All elements to which a specific class is attached will have the same style.
To classify an element add a period to the selector followed by an unique name. The name can contain characters a-z, A-Z, digits 0-9, period, hyphen, escaped characters, Unicode characters 161-255, as well as any Unicode character as a numeric code, however, they cannot start with a dash or a digit. (Note: in HTML the value of the CLASS attribute can contain more characters). (Note: text between /* and */ are my comments).
CSS
P.name1 {color: red} /* one class of P selector */
P.name2 {color: blue} /* another class of P selector */
.name3 {color: green} /* can be attached to any element */
HTML
<P>This paragraph will be red</P>
<P>This paragraph will be blue</P>
<P>This paragraph will be green</P>
<LI>This list item will be green</LI>
It is a good practice to name classes according to their function than their appearance; e.g. P.fotnote and not P.green. In CSS1 only one class can be attached to a selector. CSS2 allows attaching more classes, e.g.:
P.name1.name2.name3 {declaration} <P>This paragraph has three classes attached</P>
more:What is CLASS selector
March 28, 2010, 7:59 am
Class selector is a “stand alone” class to which a specific style is declared. Using the CLASS attribute the declared style can then be associated with any HTML element. The class selectors are created by a period followed by the class’s name. The name can contain characters a-z, A-Z, digits 0-9, period, hyphen, escaped characters, Unicode characters 161-255, as well as any Unicode character as a numeric code, however, they cannot start with a dash or a digit. (Note: in HTML the value of the CLASS attribute can contain more characters).It is a good practice to name classes according to their function than their appearance.
.footnote {font: 70%} /* class as selector */
<ADDRESS/>This element is associated with the CLASS footnote</ADDRESS>
<P>And so is this</P>
