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How do I concatenate or merge arrays in Swift?
...g a new array
let c = a + b
print(c) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
or append one array to the other with += (or append):
a += b
// Or:
a.append(contentsOf: b) // Swift 3
a.appendContentsOf(b) // Swift 2
a.extend(b) // Swift 1.2
print(a) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
...
Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]
I've seen Bash scripts test for a non-zero length string in two different ways. Most scripts use the -n option:
6 Answers...
What characters do I need to escape in XML documents?
What characters must be escaped in XML documents, or where could I find such a list?
9 Answers
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What is an application binary interface (ABI)?
... concept of an API. If you want to use the features of, say, some library or your OS, you will program against an API. The API consists of data types/structures, constants, functions, etc that you can use in your code to access the functionality of that external component.
An ABI is very similar....
How to close Android application?
... in a helper class and then call it whenever the app needs to be killed. For example in the destroy method of the root activity (assuming that the app never kills this activity):
Also Android will not notify an application of the HOME key event, so you cannot close the application when the HOME ke...
What is SOA “in plain english”? [closed]
...ere, SOA there but I cannot understand exacly what it is and what is used for. Was it some simple concept and later evolved into something huge or what?
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How to convert a string to lower case in Bash?
...cho "$a" | awk '{print tolower($0)}'
hi all
Non-POSIX
You may run into portability issues with the following examples:
Bash 4.0
$ echo "${a,,}"
hi all
sed
$ echo "$a" | sed -e 's/\(.*\)/\L\1/'
hi all
# this also works:
$ sed -e 's/\(.*\)/\L\1/' <<< "$a"
hi all
Perl
$ echo "$a" | ...
What are the main performance differences between varchar and nvarchar SQL Server data types?
I'm working on a database for a small web app at my school using SQL Server 2005 .
I see a couple of schools of thought on the issue of varchar vs nvarchar :
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When to use the different log levels
There are different ways to log messages, in order of fatality:
18 Answers
18
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Group vs role (Any real difference?)
...al difference between group and role? I've been trying to figure this out for some time now and the more information I read, the more I get the sense that this is brought up just to confuse people and there is no real difference. Both can do the other's job. I've always used a group to manage users ...