This question already has answers here:
Purpose of asterisk before a CSS property
(6 answers)
Closed 9 years ago.
I found these lines
width : 74.358974359%;
*width: 74.30578286963829%;
in style sheet but i can't understand what is the meaning of *width ???
i searched in Google but no result found.
thanks in advance
That's a CSS hack that targets Microsoft IE 7 only.IE7 will honor that CSS rule even though it is invalid due to the asterisk. All other browsers will ignore it. So by using the asterisk you can effectively target IE7 only. This is usually done to compensate for IE7 behaving badly and rendering content incorrectly and needing a special rule to correct it.
It is a syntax error. It's one of the IE hacks. Internet Explorer parses CSS in a slightly different way, allowing for certain hacks that will be ignored in other browsers. You can target different versions of IE with different hacks.
So in CSS, it makes the property name invalid and stops it being parsed.
Thanks to bugs in browsers, it is sometimes ignored. This effectively causes the property to apply only to browsers featuring that particular bug — IE7.
In general, it should be avoided in favour of conditional comments.
Unrecommended hacks
Related
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
CSS reset - purpose of asterik within a style
I was reading through the CSS styles for HTML5BoilerPlate, and I came across this unfamiliar line:
button, input, select, textarea {
font-size: 100%; margin: 0; vertical-align: baseline; *vertical-align: middle;
}
In particular, the second ****vertical-align***, why call twice and put an asterisk in front of it.
If anyone knows the name of the technique or why it's used, it would be a great help
Thanks!
-Adrian
It's a nasty hack that can be used to target older versions of IE (other browsers ignore the invalid asterisk-prefixed value). Definitely not a good idea, far better to use IE conditional stylesheets or similar techniques.
It's a CSS hack for Internet Explorer browsers:
*property: value
If you add a non-alphanumeric character such as an asterisk (*) immediately before a property name, the property will be applied in IE and not in other browsers. Unlike with the hyphen and underscore method, the CSS specification makes no reservations for the asterisk as a prefix, so use of this hack could result in unexpected behavior as the CSS specifications evolve.
property: value applies the property value in IE 7 and below. It may or may not work in future versions. Warning: this uses invalid CSS.
from here
This is a css hack and used to target IE7 browser.
For more reference see How to Target IE6, IE7, and IE8 Uniquely with 4 Characters
It's an IE6 hack. If you put the * in front of a CSS attribute, it will only be read by IE6. Since IE6 usage is now down to 1% of the world, we can forget about this hack (unless you live in China)
That title isn't quite as crazy it seems. I promise!!
While researching for another question, I noticed the following in Stack Overflow's stylesheets:
...
width: auto;
...
width: 650px!ie7;
padding-bottom: 20px!ie7;
...
Is this an odd type of conditional styling? Is this a mistake? Assuming it isn't a mistake, does this work with all IE versions? Is there a way of specifying that a given rule should only be applied to versions of IE greater than – say – 7?
I have never encountered of this before – I've always used conditional comments for IE-specific styles (and for what it's worth, I prefer keeping all IE-specific styles completely separate).
I have heard of this before, but not with the exact text !ie7.
I found a reference here: http://www.javascriptkit.com/dhtmltutors/csshacks3.shtml
!ie
Internet Explorer 7 fixed one of the
issues with the !important identifier,
but it still has problems when the
identifier has an error in it. If an
illegal identifier name is used in
place of important, Internet Explorer
7 and below will handle the property
normally instead of failing.
Therefore, in any style declaration
block, you can include properties
intended to only apply to Internet
Explorer and add an !ie identifier.
Almost any word can be used in place
of ie.
The !ie identifier allows the property
to be applied in IE 7 and below. It
may or may not work in future
versions. Warning: this uses invalid
CSS!
So, width: 650px!ie7; will be applied in only IE 7 and below.
The actual text ie7 is not required, but it's a sensible string to use, to remind people of the purpose behind the hack.
This question already has answers here:
Purpose of asterisk before a CSS property
(6 answers)
Closed 3 years ago.
I know what an asterisk does in a selector for CSS (What does an Asterisk do?), but what does it do in a property name? Here is an example of CSS used by YUI. I don't know what the *display does.
.yui-button .first-child
{
display:block;
*display:inline-block;
}
It is a syntax error. So in CSS, it makes the property name invalid and stops it being parsed.
Thanks to bugs in browsers, it is sometimes ignored. This effectively causes the property to apply only to browsers featuring that particular bug — IE7.
In general, it should be avoided in favour of conditional comments.
It's an IE hack. The second declaration will be applied by IE7 and older (thus overriding the first declaration), while other browsers will ignore it and continue applying the first declaration instead.
Also, this is invalid CSS syntax.
its like the underscore for ie6. but for ie7
if you put the asterisk the property will only be used in ie7 and older browsers.
its an hack...
It's one of the IE hacks. Internet Explorer parses CSS in a slightly different way, allowing for certain hacks that will be ignored in other browsers. Google for it. You can target different versions of IE with different hacks.
This question already has answers here:
Detecting IE version using CSS Capability/Feature Detection
(18 answers)
Closed 5 months ago.
input,textarea,select{font-family:inherit;font-size:inherit;font-weight:inherit;}
input,textarea,select{*font-size:100%;}
This is from the YUI reset css. What does the * before font-size:100% do?
This is an IE hack. The second line is only correctly parsed and executed by IE 7 and below. See http://www.webdevout.net/css-hacks#unrecommended-asterisk_prefix for more information.
Edit: One remark on using such (invalid!) CSS: please don't. There are plenty of ways of keeping your CSS clean of such mess. You'll never know what behavior IE9 might bring. Better to put these kind of hacks in a separate CSS file which can then be included through conditional comments.
To be more precise: IE6/7 doesn't support font-size: inherit. This hack is supposed to achieve the goal anyway.
I think it's a hack to make that definition only apply to IE 7 or less while being ignored by other browser as an asterisk is not a legal character before an attribute name.
As already told, those are hack to target specific browsers. Marc's suggestion is quiet right, and here's a link to give you an kick start:
http://www.webdevout.net/css-hacks
This question already has answers here:
Detecting IE version using CSS Capability/Feature Detection
(18 answers)
Closed 5 months ago.
I have been looking at a hack to solve a CSS problem I have. I have used one to create a custom rule for Internet Explorer.
margin-top:45px;
*margin-top:0px;
Does this hack apply to all IE browsers? Does this hack appear in any versions of Firefox or Safari?
This applies to IE7 and below. But be aware that this is not valid CSS, and it could break at any time. See here for a more comprehensive list of the various CSS hacks and which browsers they affect.
Although Internet Explorer 7 corrected its behavior when a property name is prefixed with an underscore or a hyphen, other non-alphanumeric character prefixes are treated as they were in IE6. Therefore, if you add a non-alphanumeric character such as an asterisk (*) immediately before a property name, the property will be applied in IE and not in other browsers. Unlike with the hyphen and underscore method, the CSS specification makes no reservations for the asterisk as a prefix, so use of this hack could result in unexpected behavior as the CSS specifications evolve.
I'd strongly recommend reconsidering whether you really need this hack, and if there isn't a better way to do what you want.