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Difference between map and collect in Ruby?
... and multi-paradigm languages as well: In C++'s Standard Template Library, it is called transform, in C# (3.0)'s LINQ library, it is provided as an extension method called Select. Map is also a frequently used operation in high level languages such as Perl, Python and Ruby; the operation is called m...
const char* concatenation
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edited Jan 4 '10 at 5:18
answered Jan 3 '10 at 14:05
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社交应用组件 · App Inventor 2 中文网
...国内无法使用）
A non-visible component that enables communication with Twitter. Once a
user has logged into their Twitter account (and the authorization has been confirmed successful
by the IsAuthorized event), many more operations are available:
Searching Twitter for tweets or labels ...
What's the difference between tag and release?
Using GitHub's API, I can't get the releases list, but I can get the tags list.
1 Answer
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'IF' in 'SELECT' statement - choose output value based on column values
...ee http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of a null amount:
SELECT id,
IF(type = 'P', IFNULL(amount,0), IFNULL(amount,0) * -1) as amount
FROM report
The part IFNULL(amount,0) means when am...
How do I create a variable number of variables?
...ou can use variable key names to achieve the effect of variable variables without the security risk.
>>> x = "spam"
>>> z = {x: "eggs"}
>>> z["spam"]
'eggs'
For cases where you're thinking of doing something like
var1 = 'foo'
var2 = 'bar'
var3 = 'baz'
...
a list may ...
How to copy Docker images from one host to another without using a repository
How do I transfer a Docker image from one machine to another one without using a repository, no matter private or public?
1...
Converting Epoch time into the datetime
... Where did the time "1347517491247" come from in your example? Is it a real time value you're using?
– ron rothman
Sep 13 '12 at 6:39
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How to increase request timeout in IIS?
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edited Dec 19 '15 at 15:44
HasanG
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How to center a button within a div?
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Updated Answer
Updating because I noticed it's an active answer, however Flexbox would be the correct approach now.
Live Demo
Vertical and horizontal alignment.
#wrapper {
display: flex;
align-items: center;
justify-content: center;
}
Just horizontal (as l...