This question already has answers here:
How can I pass a slice as a variadic input?
(3 answers)
Closed 4 years ago.
I need to initialize gocql with multiple ips, I want to pass the ips from a variable/constant.
How to pass some thing like
gocql.NewCluster(ipvalues)
instead of using
gocql.NewCluster("127.0.0.1", "127.0.0.2")
i want to pass the list of ips through a variable something like an array.
As you can see, gocql.NewCluser takes a variadic parameter, which means you can pass multiple values separated with commas to the function.
In go, you just need to make your ipvalues variable be a slice of strings and pass it like this:
ipvalues := []string{"127.0.0.1", "127.0.0.2"}
gocql.NewCluster(ipvalues...)
This will have the same effect as writing gocql.NewCluster("127.0.0.1", "127.0.0.2")
See the golang spec for more information on this feature
Related
This question already has answers here:
JMeter retrieve value of value
(2 answers)
Closed 1 year ago.
''
I want to pass parameter inside parameter.
For ex. ${var1${var2}} something like this.
I am taking this variables from Test plan's user defined variables.
''
Try this one: ${__V(var1${var2})}
Jmeter documentation
You can use the __V() function. It will combine the two variables.
You can refer this for more details.
https://www.blazemeter.com/blog/here%E2%80%99s-what-do-combine-multiple-jmeter-variables
This question already has answers here:
Multiple values in single-value context
(6 answers)
Closed 7 years ago.
Is there any way in Go to do this:
segment := Segment{
CumulativeDistanceMm: strconv.Atoi(record[9]),
Length: strconv.Atoi(record[1]),
LinkId: strconv.Atoi(record[8]),
SegmentId: strconv.Atoi(record[2]),
}
The error that I get is that strconv.Atoi returns multiple values so I can't assign it directly to the struct properties. If it was a variable I could use the underscore to ignore the second value. Can I do something similar for structs?
strconv.Atoi can fail and you have to deal with this failure. If such failures are absolutely impossible you would write a function func MustAtoi(s string) int which panics on failure and use that one in your struct initialization.
In Go doing some programming instead of using syntactical sugar or fancy syntax is common.
Most probably you should rethink your error handling.
This question already has answers here:
How can I pass a slice as a variadic input?
(3 answers)
Closed 7 years ago.
filepath.Join method takes in a ...string argument but I have a []string that I would like pass in. When I attempt to do this I get the following error:
cannot use append(elems, spadePath) (type []string) as type string in argument to filepath.Join
Is there a way to convert between a []type and a ...type?
Found a way to do this by appending the ... to your slice when being passed in as an argument.
For example, I was originally trying to call make the following call which was yielding the error:
filepath.Join(append(elems, basePath))
but I corrected it by appending ... in the argument:
filepath.Join(append(elems, basePath)...)
This question already has an answer here:
Does Swift have something like "ref" keyword that forces parameter to be passed by reference?
(1 answer)
Closed 8 years ago.
Swift has the inout keyword to pass a primitive argument by reference. When would I use this over just passing it by value?
Edit: I realize that you can use this to change its value, but why not just pass it by value and assign it the corresponding value in the tuple returned by the function?
You would do that if you wanted to modify the original value instead of just a copy. However, I would argue that you should just return the new value since you can return multiple values in Swift.
This seems to be a plausible reason:
"Maybe the existing body of Objective C libraries have a lot of out parameters, and they didn't want to wrap them all for Swift."
http://blog.lexspoon.org/2014/06/my-analysis-of-swift-language.html
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How to pass an associative array as argument to a function in Bash?
I declare my hash array:
declare -A some_array
And I declare my function:
some_function() {
..
}
How can I send the array as an argument to the function in order to access it?
I know that I can use it as a global variable, but it's not the way out when I have a lot of hash arrays I want to use with some function.
If there is no way to do it, how can I assign to the one hash array value of other?
Access it as a global variable (simply refer to it by name inside your function). There is no array passing in Bash. There are awkward techniques that try to do this, but I recommend avoiding the mess.
Other options include writing your entire script in a language such as Python or Perl which supports passing arrays, hashes or their references.
In Bash 4.3 or later you can use name references, but there are caveats.