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What is an inout parameter?

Inout Parameter

What is an inout parameter

  • Value is passed into the function, it is then modified by the function and is passed back out of the function to replace the original value.
  • Pass-by-value-and-copy-back NOT pass-by-reference.
  • Every inout parameter needs a & prefix.
  • Must pass in a variable.
  • If you pass in an UnsafeMutablePointer as a parameter but now we are passing by reference. Not recommended to use this if possible.
func increment(value: inout Int) {
  value += 1

var value = 0
increment(value: &value)

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