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Function declaration to return anything, also void?


Function declaration to return anything, also void?

By : user2948316
Date : November 14 2020, 04:48 PM
hop of those help? If you add a second generic parameter with no constraints, and type the function to return it, then any return value would be accepted:
code :
extension Array {
    func forEach<U>(function: (Element) -> U) {
        for e in self {
            function(e)
        }
    }
}

func f(i: Int)->Int {
    return i * 2
}

func g(i: Int) -> Double {
    return Double(0.0)
}

func h(i: Int) {
    println("\(i)")
}

let a = [1,2,3]
a.forEach(g)  // U will be an Int
a.forEach(f)  // U will be a Double
a.forEach(h)  // U will be a ()
// function that does something side-effecty, but
// if it achieves some goal, exist early
func someFunc(a: [Int]) {
    a.forEach { i -> () in
        // goal achieved early,
        // return from func
        return
    }
    assert(false)
}


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c function declaration explanation on argument with type "void(*fcn)(void*)"

c function declaration explanation on argument with type "void(*fcn)(void*)"


By : user7046431
Date : March 29 2020, 07:55 AM
wish of those help I encountered the following line as a C function declaration. I'm confused by the type of the first argument passed in. Can anyone explain how to understand the type of the first argument?
code :
void (*fcn) (void *)
Why is this head method without a return type or void declaration?

Why is this head method without a return type or void declaration?


By : prasad iyer
Date : March 29 2020, 07:55 AM
This might help you I have a question. I have these attributes:
code :
public dispenser (){
  x=9;
  y=0;
}
public void two (){
   x=y-1;
}
Unexpected non-void return value in void function, return multiple values

Unexpected non-void return value in void function, return multiple values


By : Salman Khan
Date : March 29 2020, 07:55 AM
will help you First mistake here is that Alamofire.request... is asynchronous. So you can't return a value fetched using that in your function.
The reason you are getting an error is because you are no longer in your function when you are trying to return. You are in the function that is the completion handler of the Alamofire request.
code :
func calculateDistance(_ firstLat: Double, _ firstLong: Double, _ secondLat: Double, _ secondLong: Double, completionHandler: @escaping (Double, Double, String) -> ()) {

    let URL = "https://maps.googleapis.com/maps/api/distancematrix/json?units=imperial&origins=\(firstLat),\(firstLong)&destinations=\(secondLat),\(secondLong)&key=KEYID"
        Alamofire.request(URL).responseJSON { response in
            if let value = response.result.value {
                let json = JSON(value)
                let distance = json["rows"][0]["elements"][0]["distance"]["value"].double! / 1000 // Double
                let price = distance * 1.0 // Double
                let duration = json["rows"][0]["elements"][0]["duration"]["text"] // String
                completionHandler(distance, price, duration) // Keep getting this error on this line
            }
        }
    }
}
calculateDistance(1, 2, 3) { (distance, price, duration) in
    // do something with the distance price and duration
}
Unexpected non-void return value in void function for return true

Unexpected non-void return value in void function for return true


By : Aloyse Bey
Date : March 29 2020, 07:55 AM
With these it helps The method signature should have -> Bool at the end. This tells the compiler that the method will return a boolean value. Check this.
warning: ‘return’ with a value, in function returning void return next; ex19.c:95:10: error: void value not ignored as i

warning: ‘return’ with a value, in function returning void return next; ex19.c:95:10: error: void value not ignored as i


By : Jeanielmj
Date : March 29 2020, 07:55 AM
wish helps you I am going through the Learn Code the hard way book and stuck on exercise 19 http://c.learncodethehardway.org/book/ex19.html. I got desperate, copied and pasted the code, yet still I am getting errors: , This line:
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