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What is the difference between properties and attributes in HTML?
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When writing HTML source code, you can define attributes on your HTML elements. Then, once the browser parses your code, a corresponding DOM node will be created. This node is an object, and therefore it has properties.
For instanc...
扩展App Inventor：具有多点触控和手势检测功能 · App Inventor 2 中文网
... Inventor：具有多点触控和手势检测功能
Xinyue Deng (dxy0420@mit.edu)
Hal Abelson (hal@mit.edu)
Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology
77 Massachusetts Avenue, Cambridge, MA 02139, USA
ABSTRACT
MIT App Inventor is a block-ba...
Private vs Public in Cache-Control
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The only difference is that with Private you are not allowing proxies to cache the data that travels through them. In the end, it all boils down to the data contained in the pages/files you are sending.
For example, your ISP could have an invisible prox...
HTML5 best practices; section/header/aside/article elements
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Actually, you are quite right when it comes to header/footer. Here is some basic information on how each of the major HTML5 tags can/should be used (I suggest reading the full source linked at the bottom):
section – Used for grouping tog...
What is the difference between null and undefined in JavaScript?
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alert(typeof TestVar); //shows undefined
null is an assignment value. It can be assigned to a variable as a representation of no value:
var TestVar = null;
alert(TestVar); //shows null
alert(typeof TestVar); //shows object
From the preceding examples, it is clear that undefined and null are ...
How does Apple find dates, times and addresses in emails?
... email contains a date, time or location, the text becomes a hyperlink and it is possible to create an appointment or look at a map simply by tapping the link. It not only works for emails in English, but in other languages also. I love this feature and would like to understand how they do it.
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Adding hours to JavaScript Date object?
It amazes me that JavaScript's Date object does not implement an add function of any kind.
14 Answers
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What was the strangest coding standard rule that you were forced to follow? [closed]
When I asked this question I got almost always a definite yes you should have coding standards.
112 Answers
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What is the difference between pip and conda?
...ager for python packages. However, I saw the installation on IPython's website use conda to install IPython.
12 Answers
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SQLAlchemy: cascade delete
I must be missing something trivial with SQLAlchemy's cascade options because I cannot get a simple cascade delete to operate correctly -- if a parent element is a deleted, the children persist, with null foreign keys.
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