how to setup a operation queue that downloads images asynchronously in swift

To setup an operation queue that downloads images asynchronously in Swift, follow these steps:

1. Create an OperationQueue instance:

   main.swift
   let operationQueue = OperationQueue()
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2. Create a new Operation subclass that will be responsible for downloading images. In the main method of this subclass, fetch image data asynchronously and store it in a property:

   main.swift
   class ImageOperation: Operation {
       
       var imageUrl: URL
       var imageData: Data?
       
       init(imageUrl: URL) {
           self.imageUrl = imageUrl
           super.init()
       }
       
       override func main() {
           let task = URLSession.shared.dataTask(with: imageUrl) { (data, response, error) in
               guard let data = data else { return }
               self.imageData = data
               self.isFinished = true
           }
           task.resume()
       }
   }
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3. Create an instance of ImageOperation for each image you want to download, passing in the URL of the image:

   main.swift
   let imageUrls: [URL] = [url1, url2, url3]
   var operations: [ImageOperation] = []
   
   for imageUrl in imageUrls {
       let operation = ImageOperation(imageUrl: imageUrl)
       operations.append(operation)
   }
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4. Add all of the ImageOperation instances to the operation queue:

   main.swift
   operationQueue.addOperations(operations, waitUntilFinished: false)
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5. When the image downloads are complete, use the imageData property of each ImageOperation instance to create UIImage objects:

   main.swift
   for operation in operations {
       guard let imageData = operation.imageData else { continue }
       let image = UIImage(data: imageData)
       // Do something with the image...
   }
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Note: If you need to display the images in a UI component, make sure to update the UI on the main thread.