Control Transfer Statements in swift

continue, break, fallthrough in swift

In this article, we will look at the continue, break, fallthrough keywords in swift

Continue: A continue statement ends program execution of the current iteration of a loop statement and move to next iteration.

Ex: Increment the values of odd number in the array

func increment(array: [Int]) -> [Int] {
    var output: [Int] = []
   
    for number in array {
    ///Check if value is even
        if number % 2 == 0 { 
        ///number append to output array and move to next iteration      
           output.append(number)
           continue
        }
       ///This statement is skipped for even number 
       output.append(number + 1)
    }
    return output
}

swiftnil.com: Continue statement

--------------------------
Input: increment(array: [1,2,3,4,5,6,7,8])
Output: [2, 2, 4, 4, 6, 6, 8, 8]
--------------------------

Break: The Break statement exit the execution of an entire control flow immediately.

Ex: Increment the values the array until value is `n`

func increment(array: [Int], until: Int) -> [Int] {
   var output: [Int] = []
    
   for number in array {
      if number == until {
         break
      }
      output.append(number + 1)
   }
   return output
}

swiftnil.com: Break statement

--------------------------
Input: increment(array: [1,2,3,4,5,6,7,8], until: 5)
Output: [2, 3, 4, 5]
--------------------------

Fallthrough: In Swift, switch statements exist the execution as soon as case is matched so, fallthrough is used to continue to next case even after the case is matched

var index = 10

switch index {
   case 100 :
      print( "Value of index is 100")
      fallthrough
   case 10,15 :
      print( "Value of index is either 10 or 15")
      fallthrough
   case 5 :
      print( "Value of index is 5")
   default :
      print( "default case")
}

swiftnil.com: Fallthrough statement

Reference

https://docs.swift.org/swift-book/LanguageGuide/ControlFlow.html

Thanks for reading, do visit www.swiftnil.com for more such articles.