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