How to convert an Int into NSData in Swift?

Question

In Objective-C I use the following code to

1. Convert an Int variable into NSData, a packet of bytes.

   int myScore = 0;
   NS         
   
   
           

Answer 1

Swift 5, add an other option.

NSData is old, still effective

Write Data:

let buffer = NSMutableData()
let size = MemoryLayout.size
let big = 1000
let small = 10
withUnsafeBytes(of: big, { (p) in
      let bufferPointer = p.bindMemory(to: UInt.self)
      if let address = bufferPointer.baseAddress{
             buffer.append(address, length: size)
      }
})

withUnsafeBytes(of: small, { (p) in
      let bufferPointer = p.bindMemory(to: UInt.self)
      if let address = bufferPointer.baseAddress{
           buffer.append(address, length: size)
      }
 })

Read data:

if let d = buffer.copy() as? Data{
     var big: UInt = 0
     var small: UInt = 0
     let size = MemoryLayout.size
     let meta = NSData(data: data)
     meta.getBytes(&big, range: NSRange(location: 0, length: size))
     meta.getBytes(&small, range: NSRange(location: size, length: size))

     print("big:", big, "\nsmall:", small)
    //  big: 1000 
    //  small: 10 
}

You know the memory layout, the data put in the memory,

Then put them out exactly.

unsafe method is funny