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Swift variable name with ` (backtick)
(3 answers)
Closed 2 years ago.
What does the `` around default mean in the following code below?
In what cases would you want to use it?
static let `default` = User(id: UUID(), name: "Anonymous")
Thank you in advanced
The backticks allow you to use restricted keywords in places where they otherwise couldn't be used, such as variable names.
default is a restricted keyword in Swift, but by putting backticks around it, it becomes a valid variable name.
Without the backticks, your code would result in the error
Keyword 'default' cannot be used as an identifier here
Related
This question already has answers here:
Can I dynamically get a list of functions or function names from any Perl module?
(3 answers)
How do I list available methods on a given object or package in Perl?
(5 answers)
List all the subroutine names in perl program
(3 answers)
Get list of methods/functions defined explicitly in a module
(1 answer)
Closed 6 months ago.
First of all, I am entirely new in perl so I apologize if this is a rather basic question.
We have a perl script that calls on a module — lets name it module_x
It’s called in the script using this line.
require module_x
Sadly, this does not have a documentation and we can’t access the server where this script is.
Is there a way to know what functions are available in the module? Similar to desc in python.
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How to execute multiple statements in a MATLAB anonymous function?
(5 answers)
Closed 7 years ago.
Is it possible to create multiline anonymous function in Matlab?
There are no appropriate examples in documentation, but also no direct denials. In web discussions I found some derisions of askers as if it silly wish. Nowadays, when most languages introducing lambda expressions with multiline capability this looks strange.
No, unfortunately this is not possible.
This question already has answers here:
Create variables with names from strings
(6 answers)
Closed 7 years ago.
Assume the variable FileName contains a string such as Name1. How do I make a variable with the name Name1?
The example 4 at this page seems to be similar, but I cant get it to work. Is it the right way to do it?
http://se.mathworks.com/help/matlab/ref/genvarname.html
What you see in "Example 4" is accused as bad programming style. The documentation also contains a section why to avoid eval.
I would recommend a struct with dynamic field names to achieve similar.
filename='name1';
mydata=struct();
mydata.(genvarname(filename))=load(filename);
Besides better performance, you also get additional functionality when handling multiple files. For example structfun to apply a function to all your data or fieldnames to get all filenames.
For what you want to do, the eval function is there for you:
FileName = 'Name1';
eval([FileName ' = 18;']); % Executes "Name1 = 18;"
and now the variable Name1 is created and has a value of 18.
The function genvarname has a different purpose, which is to generate acceptable and non-conflicting variable names, and not the variables themselves.
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How do I access program arguments in Swift?
(6 answers)
Closed 8 years ago.
I'm writing a command line app using Swift but I'm not sure how to get access to the arguments passed in. In C/Obj-c it seems relatively painless but if I try:
argv[0]
I get an error: Use of unresolved identifier 'argv'
There are two ways to do this:
The constants C_ARGC and C_ARGV. They are analogous to the argc and argv you'd see in a main() function.
The CommandLine.arguments array will contain all of the arguments to the process. (In Swift 2, CommandLine was called Process)
This question already has answers here:
When should I use the & to call a Perl subroutine?
(4 answers)
Closed 9 years ago.
Every now and then I see Perl scripts where subroutines are called with a leading '&'.
Is this legacy, or does it give any benefit?
As calling the subroutine without the ampersand sign works as well.
sub mysub {
print "mysub\n";
}
mysub;
&mysub;
Thx/Hermann
Calling with & is generally a code smell that somebody doesn't know what they're doing and are in a Perl4 mindset. In your specific example, it works exactly the same. However, calling with & disables function prototypes, so advanced users may use it in certain circumstances. You should expect to see a comment why next to the call in that case.