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Centering a background image, using CSS
...age: url(path-to-file/img.jpg);
background-repeat:no-repeat;
background-position: center center;
That should work.
If not, why not make a div with the image and use z-index to make it the background? This would be much easier to center than a background image on the body.
Other than that try:
b...
Row Offset in SQL Server
... starting at a given offset? For example, in another type of SQL database, it's possible to do:
16 Answers
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What's the fastest way to merge/join data.frames in R?
... and merge approaches are not the same. Match is, of course, faster since it is not doing as much. In particular it never looks for duplicate keys. (continued after code)
DF1 = data.frame(a = c(1, 1, 2, 2), b = 1:4)
DF2 = data.frame(b = c(1, 2, 3, 3, 4), c = letters[1:5])
merge(DF1, DF2)
b a c...
How to avoid isset() and empty()
... the E_NOTICE error level, because the existence of variables is not explicitly checked using isset() and consorts.
11 An...
Difference between the Apache HTTP Server and Apache Tomcat? [closed]
What is the difference in terms of functionality between the Apache HTTP Server and Apache Tomcat?
8 Answers
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How to atomically delete keys matching a pattern using Redis
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Starting with redis 2.6.0, you can run lua scripts, which execute atomically. I have never written one, but I think it would look something like this
EVAL "return redis.call('del', unpack(redis.call('keys', ARGV[1])))" 0 prefix:[YOUR_...
How does the Java 'for each' loop work?
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for (Iterator<String> i = someIterable.iterator(); i.hasNext();) {
String item = i.next();
System.out.println(item);
}
Note that if you need to use i.remove(); in your loop, or access the actual iterator in some wa...
How to change an element's title attribute using jQuery
I have an form input element and want to change its title attribute. This has to be easy as pie, but for some reason I cannot find how to do this. How is this done, and where and how should I be searching on how to do this?
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How to prevent sticky hover effects for buttons on touch devices
I have created a carousel with a previous and a next button that are always visible. These buttons have a hover state, they turn blue. On touch devices, like iPad, the hover state is sticky, so the button stays blue after tapping it. I don't want that.
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Can I safely delete contents of Xcode Derived data folder?
I am running low on disk space and checked through a third party utility that among other things that ~/Library/Developer/Xcode/DerivedData directory is taking about 22GB of disk space.
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