This document discusses control structures in Swift, including branching/selection statements like if, else if, switch statements; looping/iteration statements like for-in, while, repeat-while loops; and jumping statements like break, continue. It provides examples of how to use each statement type and explains their syntax and usage. Key control structures covered are if/else, switch, for-in, while and repeat-while loops, and the break, continue, and fallthrough statements.

1. Control Structures in Swift
> If Statement
> If Else Statement
> If Else If Statement
> Nested If Statement
> Switch Statement
Branching/
Selection
Statements
Looping/
Iteration
Statements
Jumping/
Jump
Statements
> For In Loop
> While Loop
> Repeat While Loop
> Break
> Continue
> Fallthrough
Control
Structures

2. Branching/Selection Statements
• If Statement
• If Else Statement
• If Else If Statement
• Nested If Statement
• Switch Statement

3. If Statements
• Indicates decision is to be made
• Contains an expression that can be true or false
• Performs action only if the condition is true
• Single-entry/single-exit
• Syntax:
if expression
{
execute statement if expression is true
}
normal statements after if..

4. If Statements

5. IF Statement Example
var grade = 66
if grade>=60
{
print(“You are passed.”)
}
Result
You are passed

6. IF ELSE Statement
• Indicates decision is to be made
• Contains an expression that can be true or false
• Performs different action if the condition is true and
different action if condition is false
• Single-entry/Two-exit
• Syntax:
if expression
{ execute statement if expression is true }
else
{ execute statement if expression is false }

7. IF ELSE Statement

8. IF ELSE Statement
• Indicates decision is to be made
• Contains an expression that can be true or false
• Performs different action if the condition is true and
different action if condition is false
• Single-entry/Two-exit
• Syntax:
if expression
{ execute statement if expression is true }
else
{ execute statement if expression is false }

9. IF ELSE Statement Example
let grade = 66
if grade>=60
{
print(“You are passed.”)
}
else
{
print(“You are Failed.”)
}
Result
You are passed.

10. IF ELSE IF Statement
• Indicates decision after another decision is to be
made(i.e. Multiple Cases)
• Contains an expression that can be true or false
• Performs again expression check if the condition is
false
• Syntax:
if expression
{ execute statement if expression is true }
else if expression
{ execute statement else if expression is true}

12. IF ELSE IF Statement
var medical = true
var attendance = 70
if attendance>=75
{
print("Eligible for exam")
}
else if medical == true
{
print("Eligible for exam with medical")
}

13. NESTED IF Statement
• If inside another If
• Indicates decision after another decision is to be
made
• Performs again expression check if the condition is
true
• Syntax:
if expression
{ if expression
{ execute statement if both if expressions are true }
}

15. NESTED IF Statement
var attendance= 80
var grade=66
if attendance>= 75
{
if ( grade >= 60 )
{
print(“You are Passed“);
}
}

16. Switch Statement
• Contains multiple cases(Multiple Branching
Statement)
• Single-entry/Multiple-exit
• Syntax:
switch literal
{ case value1:
execute statement if case1 matches
case value2,value3:
execute statement if case2 matches
default: execute if none case matches }

17. SWITCH Statement
var c = 3
switch c
{ case 1:
print("You got 1 diamond")
case 2:
print("You got 2 diamonds")
case 3:
print("You got 3 diamonds")
default:
print("Nothing here") }

18. SWITCH Statement
var c = 3
switch c
{ case 1,2:
print("You got 5 diamond")
case 3,4:
print("You got 10 diamonds")
case 5,6:
print("You got 15 diamonds")
default:
print("Nothing here") }
Note: switch does not
require explicit break

19. Looping/Iteration Statements
• For In Loop
• While Loop
• Do While Loop(now. Repeat While)

20. For In Loop
• Indicates Iteration/Repetition of statements
• It iterates over a sequence, such as ranges of
numbers or items in an array.
• Syntax:
for index in variable
{
statement to be executed..
}

21. For In Loop Example
var arr:[Int] = [10, 20, 30, 40]
for i in arr
{
print("Value of i is (i)")
} Result
Value of i is 10
Value of i is 20
Value of i is 30
Value of i is 40

22. For In Loop Example
for i in 1...5
{
print("(i) times 5 is (i * 5)")
} Result
1 times 5 is 5
2 times 5 is 10
3 times 5 is 15
4 times 5 is 20
5 times 5 is 25
Closed range operator

23. For In Loop Example
for i in 1..<5
{
print("(i) times 5 is (i * 5)")
} Result
1 times 5 is 5
2 times 5 is 10
3 times 5 is 15
4 times 5 is 20
Half Open range operator

24. For In Loop Example
let base = 3
let power = 4
var answer = 1
for i in 1...power
{
answer = answer * base
}
print("(base)'s power (power) is (answer)")
Result
3's power 4 is 81

25. For In Loop Example
• If you don’t need each value from a sequence, you
can ignore the values by using an underscore in place
of a variable name.
• Syntax:
for _ in variable
{
statement to be executed..
}

26. For In Loop Example
let base = 3
let power = 4
var answer = 1
for _ in 1...power
{
answer = answer * base
}
print("(base)'s power (power) is (answer)")
Result
3's power 4 is 81

27. While Loop
• Indicates Iteration/Repetition of statements
• Contains an expression that should be true in order
to perform actions repeatedly
• Keep on performing action till the condition is true.
• Syntax:
while expression
{
statement to be executed..
}

28. While Loop Example
var i = 1
while i<5
{
print("Value of i is (i)")
i = i+1
}
Result
Value of i is 1
Value of i is 2
Value of i is 3
Value of i is 4

29. (Do)Repeat While Loop
• Indicates Iteration/Repetition of statements
• Perform Operation and then check(Exit-Controlled)
• Perform action at least once even if condition is
false.
• Do while in swift is replaced by repeat while.
• Syntax:
repeat
{ statement to be executed.. } while expression

30. Repeat While Loop Example
var i = 1
repeat
{
print("Value of i is (i)")
i = i+1
} while i<5
Result
Value of i is 1
Value of i is 2
Value of i is 3
Value of i is 4

31. Jumping/Jump Statements
• Break Statement
• Continue Statement
• Fallthrough Statement

32. Break Statement
• Stops the execution of the Loop.
• Allows to exit from current Iteration.
• Mostly used with branching statements.
• Syntax:
loop
{ statement to be executed..
if expression
{ break }
}

33. Break Statement Example
var i = 1
while true
{
print("Value of i is (i)")
i = i+1
if i==5
{ break }
}
Result
Value of i is 1
Value of i is 2
Value of i is 3
Value of i is 4

34. Continue Statement
• Skip the current iteration.
• Prevent statements to be executed once only.
• Mostly used with branching statements.
• Syntax:
loop
{ statement to be executed..
if expression
{ continue }
}

35. Continue Statement Example
var cnt = 0
for i in 1...5
{
if i==2
{
continue
}
print("Start (i)")
}
Result
Start 1
Start 3
Start 4
Start 5

36. Fallthrough Statement
• By default you don’t need to mention break
explicitly while using switch cases.
• But if you need to prevent default break behavior,
you can use fallthrough statement.
• Syntax:
switch literal
{ case value1:
execute statement if case1 matches
fallthrough
default: execute if none case matches }

37. Fallthrough Statement Example
var c = 1
switch c
{ case 1:
print("You got 1 diamond")
fallthrough
case 2:
print("You got 2 diamonds")
fallthrough
default:
print("Nothing here") }
Result
You got 1 diamond
You got 2 diamonds
Nothing here

38. MCQs

39. 1. Find the output
var i=2
var j=1
while j=i ? true : false
{ print(i) }
a. Error
b. 1
c. 2
d. None of these

40. 1. Find the output
var i=2
var j=1
while j=i ? true : false
{ print(i) }
a. Error
b. 1
c. 2
d. None of these

41. 2. Find the output
var cnt = 0
for i in 2...3
{
print(i,terminator:"")
if i==2
{ continue }
else
{ print(i,terminator:""); continue }
}
a. Error
b. 223
c. 233
d. None of these

42. 2. Find the output
var cnt = 0
for i in 2...3
{
print(i,terminator:"")
if i==2
{ continue }
else
{ print(i,terminator:""); continue }
}
a. Error
b. 223
c. 233
d. None of these

43. 3. Find the output
for i in 1...3
{
print(i,terminator:"")
i = i + 2
}
a. Error
b. 13
c. 1
d. None of these

44. 3. Find the output
for i in 1...3
{
print(i,terminator:"")
i = i + 2
}
a. Error
b. 13
c. 1
d. None of these

45. 4. Find the output
for i in 1...3
{
print(i,terminator:"")
};
print(2,terminator:“1")
a. Error
b. 1232
c. 12321
d. None of these

46. 4. Find the output
for i in 1...3
{
print(i,terminator:"")
};
print(2,terminator:“1")
a. Error
b. 1232
c. 12321
d. None of these