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Why does typeof NaN return 'number'?
...e or cosine of a number which is less than −1 or
greater than +1.
All these values may not be the same. A simple test for a NaN is to test value == value is false.
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Why do we need Abstract factory design pattern?
...
All of these examples describe the Factory Method Pattern, because all of them return a single product interface. None of these is an Abstract Factory Pattern, because none of them produce a family of related product interfac...
How can I get pg_dump to authenticate properly
...ing host variable PGPASSWORD and .pgpass and neither of these two will allow me to authenticate to the database. I have chmod 'd .pgpass to appropriate permissions and also tried:
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How do I tell Git to ignore everything except a subdirectory?
I want to ignore all files in my repository except those that occur in the bin subdirectory. I tried adding the following to my .gitignore :
...
What is android:weightSum in android, and how does it work?
...e maximum weight sum, and is calculated as the sum of the layout_weight of all the children if not specified explicitly.
Let's consider an example with a LinearLayout with horizontal orientation and 3 ImageViews inside it. Now we want these ImageViews always to take equal space. To acheive this, yo...
What is the difference between Python and IPython?
... load into your own projects.
Easy to use, high performance tools for parallel computing.
Note that the first 2 lines tell you it helps you make the most of using Python. Thus, you don't need to alter your code, the IPython shell runs your python code just like the normal python shell does, o...
How to make git mark a deleted and a new file as a file move?
I've moved a file manually and then I've modified it. According to Git, it is a new file and a removed file. Is there any way to force Git into treating it as a file move?
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Make .git directory web inaccessible
...taccess file in the .git folder and put the following in this file:
Order allow,deny
Deny from all
But note, that it would be lost if you ever re-cloned the repository
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Replace one substring for another string in shell script
...ing/Suzi/$secondString}"
# prints 'I love Sara and Marry'
To replace all occurrences, use ${parameter//pattern/string}:
message='The secret code is 12345'
echo "${message//[0-9]/X}"
# prints 'The secret code is XXXXX'
(This is documented in the Bash Reference Manual, §3.5.3 "She...
Why is String immutable in Java?
...le for several reasons, here is a summary:
Security: parameters are typically represented as String in network connections, database connection urls, usernames/passwords etc. If it were mutable, these parameters could be easily changed.
Synchronization and concurrency: making String immutable aut...