CSS perguntas e respostas de entrevista
Diferencas relacionadas
Pergunta 11. Are Style Sheets case sensitive?
No. Style sheets are case insensitive. Whatever is case insensitive in HTML is also case insensitive in CSS. However, parts that are not under control of CSS like font family names and URLs can be case sensitive - IMAGE.gif and image.gif is not the same file.
Pergunta 12. How do I have a non-tiling (non-repeating) background image?
With CSS, you can use the background-repeat property. The background repeat can be included in the shorthand background property, as in this example:
body {
background: white url(example.gif) no-repeat ;
color: black ;
}
Pergunta 13. CSS is clearly very useful for separating style from content. But apparently people tend to have problems when using it for layouts. Would you say this is because people have not yet understood how to properly do layout in CSS, or is it CSS that is lacking in this area? What can be done to improve the situation? --- Would the web benefit from HTML and CSS being complemented with some kind of "layout language"?
Layout and style should be tackled by the same language and the two are intertwined. Trying to split the two is like splitting the HTML specification in two, one specification describing inline elements and the other describing block elements. It's not worth the effort. CSS is capable of describing beautiful and scalable layouts. The CSS Zen Garden has been a eye-opening showcase of what is possible today. If MS IE had supported CSS tables, another set of layouts would have been possible. So, there is still lots of potential in the existing CSS specifications which should be the next milestone.
Pergunta 14. I always wanted to have "included" substyles or "aliases" in my CSS definition, to save redundancy.
(For includes)
.class1 { color:#ff0000; }
.class2 { background-color:#ffffff; }
.class3 { include:class1,class2;font-weight:bold; }
(For aliases)
@alias color1 #ff0000;
@alias color2 #ffffff;
@alias default_image url('/img/image1.jpg');
.class1 { color:color1; }
.class2 { background-image:default_image;background-color:co lor2; }
This way we could change colors or images for a whole webpage
by editing a reduced number of lines.
Had you considered any of these ideas in the past? If so, why were they rejected?
Yes, aliases and constants have been considered. CSS is already an indirection. Instead of putting properties and values directly on elements, it associates properties and values with selectors. What you (and others) are proposing is to add another layer of indirection. By doing so, one could possible write shorter, more manageable style sheets. However, there are also some downsides. It requires a new syntactic construct (@alias) and implementations must be able to remember a list of aliases.
Pergunta 15. Styles not showing?
There are different ways to apply CSS to a HTML document with a stylesheet, and these different ways can be combined:
* inline (internal) (Deprecated for XHTML)
* embedded (internal)
* linked (external) and
* @import (external)
Note: An external stylesheet is a text file that contains only CSS Styles. HTML comments are not supposed to be in there and can lead to misinterpretation (> is the CSS "Child" selector!).
(For includes)
.class1 { color:#ff0000; }
.class2 { background-color:#ffffff; }
.class3 { include:class1,class2;font-weight:bold; }
(For aliases)
@alias color1 #ff0000;
@alias color2 #ffffff;
@alias default_image url('/img/image1.jpg');
.class1 { color:color1; }
.class2 { background-image:default_image;background-color:co lor2; }
This way we could change colors or images for a whole webpage
by editing a reduced number of lines.
Had you considered any of these ideas in the past? If so, why were they rejected? 5) Styles not showing? " />
Mais uteis segundo os usuarios:
- What is CSS?
- What are Cascading Style Sheets?
- As a reader, how can I make my browser recognize my own style sheet?
- How do I combine multiple sheets into one?
- What are Style Sheets?