Cheatsheet Swift - Execution Flow Control

May 13, 2019
swift cheatsheet

Execution Flow Control

This cheat sheet for Swift 5 contains ways of steering the logical flow of the program.

Conditional Selection

Execute only on TRUE

let a = -1
if a < 0 {
    print("Negative Value")
}

Negative Value

Select based on TRUE or FALSE

let a = 1
if a < 0 {
    print("Negative Value")
} else {
    print("Positive Value")
}

Positive Value

Select based on VALUE

let value = 2
var group: String
switch value {
case 1:
    group = "ONE"
case 2:
    group = "TWO"
case 3:
    group = "THREE"
default:
    group = "UNIDENTIFIED"
}
print(group)

TWO

Iteration

Range Based

Forward
for i in stride(from:1,to:4,by:1) {
    print(i)
}

1
2
3

var i = 1
while i <= 3 {
    print(i)
    i+=1
}

1
2
3

var i = 1
repeat {
    print(i)
    i+=1
} while i<=3

1
2
3

Backward
for index in stride(from:3,to:0,by:-1){
    print(i)
}

3
2
1

var i = 3
while i >= 1 {
    print(i)
    i-=1
}

3
2
1

var i = 3
repeat {
    print(i)
    i-=1
} while i>=1

3
2
1

Container Based

var numbers:[Int] = [1,2,3]
for number in numbers {
    print(number)
}

1
2
3

var numbers:Set<Int> = [1,2,3,1]
for number in numbers {
    print(number) //Prints without duplicates in any order
}

3
1
2

var data:[Int: String]=[1:"Julius",2:"Canute"]
for (key,value) in data {
    print("\(key)-\(value)") //Prints in any order
}

1-Julius
2-Canute

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