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Create singleton using GCD's dispatch_once in Objective-C
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This is a perfectly acceptable and thread-safe way to create an instance of your class. It may not technically be a "singleton" (in that there can only ever be 1 of these objects), but as long as you only use the [Foo sharedFoo] metho...
Java: is there a map function?
I need a map function. Is there something like this in Java already?
6 Answers
6
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In which order do CSS stylesheets override?
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The rules for CSS rule cascading are complex -- rather than trying to paraphrase them badly, I'll simply refer you to the spec:
http://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascade
In short: more specific rules override more general ones. Specificity ...
ValueError : I/O operation on closed file
Here, p is a dictionary, w and c both are strings.
2 Answers
2
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How can I view all historical changes to a file in SVN
I know that I can svn diff -r a:b repo to view the changes between the two specified revisions. What I'd like is a diff for every revision that changed the file. Is such a command available?
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How to vertically align text inside a flexbox?
...th one adjustment, to make it all work:
ul {
height: 100%;
}
li {
display: flex;
justify-content: center;
/* align-self: center; <---- REMOVE */
align-items: center; /* <---- NEW */
background: silver;
width: 100%;
height: 20%;
}
The align-self property applies to ...
List of ANSI color escape sequences
On most terminals it is possible to colorize output using the \033 ANSI escape sequence.
5 Answers
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How to “crop” a rectangular image into a square with CSS?
I know that it is impossible to actually modify an image with CSS, which is why I put crop in quotes.
10 Answers
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Is Java “pass-by-reference” or “pass-by-value”?
I always thought Java uses pass-by-reference .
81 Answers
81
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How can I run an external command asynchronously from Python?
I need to run a shell command asynchronously from a Python script. By this I mean that I want my Python script to continue running while the external command goes off and does whatever it needs to do.
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