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Easiest way to check for an index or a key in an array?
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To check if the element is set (applies to both indexed and associative array)
[ ${array[key]+abc} ] && echo "exists"
Basically what ${array[key]+abc} does is
if array[key] is set, return abc
if array[key] is not set, return nothing
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What is lexical scope?
What is a brief introduction to lexical scoping?
18 Answers
18
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What is meant by immutable?
This could be the dumbest question ever asked but I think it is quite confusing for a Java newbie.
17 Answers
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How to explain callbacks in plain english? How are they different from calling one function from ano
How to explain callbacks in plain English? How are they different from calling one function from another function taking some context from the calling function? How can their power be explained to a novice programmer?
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What is the difference between Cloud, Grid and Cluster? [closed]
What is the difference between Cloud, Cluster and Grid? Please give some examples of each as the definition of cloud is very broad. As answered in another question , can I call Dropbox, Gmail, Facebook, Youtube, Rapidshare etc. a Cloud?
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How can I declare and use Boolean variables in a shell script?
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Revised Answer (Feb 12, 2014)
the_world_is_flat=true
# ...do something interesting...
if [ "$the_world_is_flat" = true ] ; then
echo 'Be careful not to fall off!'
fi
Original Answer
Caveats: https://stackoverflow.com/a...
How is Node.js inherently faster when it still relies on Threads internally?
... 1) break due to bugs and 2) not use them as efficiently as possible. (2) is the one you're asking about.
Think about one of the examples he gives, where a request comes in and you run some query, and then do something with the results of that. If you write it in a standard procedural way, the co...
Why not inherit from List?
...some good answers here. I would add to them the following points.
What is the correct C# way of representing a data structure, which, "logically" (that is to say, "to the human mind") is just a list of things with a few bells and whistles?
Ask any ten non-computer-programmer people who are fam...
What is the difference between HTML tags and ?
... id or class , but I'm interested in knowing if there are times when one is preferred over the other.
13 Answers
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Shall we always use [unowned self] inside closure in Swift
...metimes you want the closure to capture self in order to make sure that it is still around by the time the closure is called.
Example: Making an asynchronous network request
If you are making an asynchronous network request you do want the closure to retain self for when the request finishes. That...