Swift - 오류 처리

var numerator = 10
var denominator = 0

// try to divide a number by 0
var result = numerator / denominator // error code

Swift에서 오류 처리를 위한 단계

// create an enum with error values
enum DivisionError: Error {

  case dividedByZero
}

// create a throwing function using throws keyword
func division(numerator: Int, denominator: Int) throws {

  // throw error if divide by 0
  if denominator == 0 {
    throw DivisionError.dividedByZero
  }

  else {
    let result = numerator / denominator
    print(result)
  }
}

// call throwing function from do block
do {
  try division(numerator: 10, denominator: 0)
  print("Valid Division")
}

// catch error if function throws an error
catch DivisionError.dividedByZero {
  print("Error: Denominator cannot be 0")
}

오류 처리 비활성화

enum DivisionError: Error {

  case dividedByZero
}

func division(numerator: Int, denominator: Int) throws {
  if denominator == 0 {
    throw DivisionError.dividedByZero
  }

  else {
    let result = numerator / denominator
    print("Result:", result)
  }
}

// disable error handling
try! division(numerator: 10, denominator: 5)