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postgresql - sql - count of `true` values
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Yuk. That fix is really confusing. AFAICS, it will now count true or null values. I think that rephrasing it so that you always have nullif([boolean expression], false) makes it much easier to read. You can then vary the boolean expression part to be whatever you like, in th...
What is the standard naming convention for html/css ids and classes?
...convention (if any).
Update 2012
I've changed how I program over time. I now use camel case (thisIsASelector) instead of hyphens now; I find the latter rather ugly. Use whatever you prefer, which may easily change over time.
Update 2013
It looks like I like to mix things up yearly... After switc...
Disable submit button when form invalid with AngularJS
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Sorry, I use it now. Yet, it is still disabled even when the textbox contains text
– ali
Mar 8 '13 at 17:44
1
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Use of def, val, and var in scala
...cala> def something = 2 + 3 * 4
something: Int
scala> something // now it's evaluated, lazily upon usage
res30: Int = 14
Example, val
scala> val somethingelse = 2 + 3 * 5 // it's evaluated, eagerly upon definition
somethingelse: Int = 17
Example, var
scala> var aVariable = 2 * 3...
Is there a standard way to list names of Python modules in a package?
...name):
file, pathname, description = imp.find_module(package_name)
if file:
raise ImportError('Not a package: %r', package_name)
# Use a set because some may be both source and compiled.
return set([os.path.splitext(module)[0]
for module in os.listdir(pathname)
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Checking images for similarity with OpenCV
...) that indicates how similar these images are? E.g. 100% would be returned if the same image was passed twice, 0% would be returned if the images were totally different.
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Length of a JavaScript object
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This doesn't have to modify any existing prototype since Object.keys() is now built in.
Edit: Objects can have symbolic properties which can not be returned via Object.key method. So the answer would be incomplete without mentioning them.
Symbol type was added to the language to create unique ide...
Representing graphs (data structure) in Python
...ill be the underlying structure for our Graph class. You also have to know if these connections are arcs (directed, connect one way) or edges (undirected, connect both ways). We'll handle that by adding a directed parameter to the Graph.__init__ method. We'll also add some other helpful methods.
im...
Add CSS or JavaScript files to layout head from views or partial views
...-development-only.js")" type="text/javascript"></script>
@if (IsSectionDefined("AddToHead"))
{
@RenderSection("AddToHead", required: false)
}
@RenderSection("AddToHeadAnotherWay", required: false)
</head>
View:
@model ProjectsExt.Mod...
In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
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Why is the __autoreleasing qualifier placed inbetween the stars, and not just in front of NSError**? This looks weird to me as the type is NSError**. Or is it because this is trying to indicate that the pointed-to NSError* pointer has to be qualified as po...