CSS Basics, Part 2

Question 1

CSS syntax

Answer 1

• The selector points to the HTML element you want to style.
• The declaration block contains one or more declarations separated by semicolons.
• Each declaration includes a CSS property name and a value, separated by a colon.
• A CSS declaration always ends with a semicolon, and declaration blocks are surrounded by curly braces.
• In the following example all <p> elements will be center-aligned, with a red text color:</p>

Question 2

example

Answer 2

p {
color: red;
text-align: center;
}

Question 3

element selector

Answer 3

• the element selector selects elements based on the element name.
• You can select all <p> elements on a page like this (in this case, all </p><p> elements will be center-aligned, with a red text color):
• example:
  p {
  text-align: center;
  color: red;
  }</p>

Question 4

id selector

Answer 4

• The id selector uses the id attribute of an HTML element to select a specific element.
• The id of an element should be unique within a page, so the id selector is used to select one unique element!
• To select an element with a specific id, write a hash (#) character, followed by the id of the element.
• The style rule below will be applied to the HTML element with id=”para1”:
• example:
  #para1 {
  text-align: center;
  color: red;
  }

Question 5

class Selector

Answer 5

• The class selector selects elements with a specific class attribute.
• To select elements with a specific class, write a period (.) character, followed by the name of the class.
• In the example below, all HTML elements with class=”center” will be red and center-aligned:
• exampe:
  .center {
  text-align: center;
  color: red;
  }
• You can also specify that only specific HTML elements should be affected by a class.
• In the example below, only <p> elements with class=”center” will be center-aligned:
• example:
  p.center {
  text-align: center;
  color: red;
  }
• HTML elements can also refer to more than one class.
• In the example below, the </p><p> element will be styled according to class=”center” and to class=”large”:
• example:

</p><p class="center large">This paragraph refers to two classes.</p>

Question 6

grouping selectors

Answer 6

- If you have elements with the same style definitions, like this:
h1 {
    text-align: center;
    color: red;
}

h2 {
text-align: center;
color: red;
}

p {
    text-align: center;
    color: red;
} 
- It will be better to group the selectors, to minimize the code.
- To group selectors, separate each selector with a comma.
- In the example below we have grouped the selectors from the code above:
- Example:
h1, h2, p {
    text-align: center;
    color: red;
}

Question 7

CSS comments

Answer 7

• Comments are used to explain the code, and may help when you edit the source code at a later date.
• Comments are ignored by browsers.
• A CSS comment starts with /* and ends with */. Comments can also span multiple lines:
• Example:
  p {
  color: red;
  /* This is a single-line comment */
  text-align: center;
  }

/* This is
a multi-line
comment */

Question 8

In the following declaration block, which elements are considered properties?
{font-family: Avenir, Arial, sans-serif;
font-size: 20px;
padding: 8px;}

Answer 8

• font-family, font-size, padding