Arrays and its properties IN SWIFT

1. Constants in Swift
• Constants refer to fixed values that a program may
not alter during its execution.
• Example:
let tax = 4.5

2. separator and terminator
• To separate values or variables, separator is used.
• To add something at the end, terminator is used.
• If you want to print multiple variable in 1 statement,
how to do?
var a=4
var b=4
var c=4
print(“(a)n(b)n(c))

3. separator and terminator
• By using separator example:
var a = 4
var b= 2
var c = 6
print(a,b,c, separator: ”n”)
Result
4
2
6

4. separator and terminator
• By using terminator example:
var a = 4
var b = 2
var c = 6
print(a,b,c, terminator: ”nThis is end”)
Result
4 2 6
This is end

5. separator and terminator
• By using separator and terminator together
example:
var a = 4
var b= 2
var c = 6
print(a,b,c, separator: ”n”, terminator: ”This is end”)
Result
4
2
6
This is end

6. Array
• Arrays are used to store similar kind of values.
• Array stores the values of same type.
• Syntax:
var identifier: [datatype]
OR
var identifier: [datatype] = [value1,value2,…]
} Declaration
Declaration and Initialization

7. Array
Example 1 :
var arr=[4,2,6,9,15,3]
for n in arr
{
print(n)
}
Result
4
2
6
9
15
3

8. Array
Example 2 :
var arr=["Red","Green","Yellow","Black"]
for n in arr
{
print(n)
} Result
Red
Green
Yellow
Black

9. Empty Array
• Creating an array without any value is called Empty
Array.
• Example:
var emptyArray: [Int] = [ ]
print(emptyArray)
Result
[ ]

10. count property of Array
• To get the number of elements in an array.
• Example:
var noOfElements = [1, 2, 3, 10, 100]
print(noOfElements.count)
Result
5

11. isEmpty property of Array
• To check the number of elements in an array are
zero or not(i.e. count is zero or not).
• Example:
if cart.isEmpty {
print("The cart is empty.")
} else {
print("The cart is not empty.")
}

12. Adding values to Array
• You can add elements to the end of an array using
the append method.
• Example:
var arr: [Int] = [1,2,3,4,5]
for i in 6...9 {
arr.append(i)
}
print(arr)
Result
[1, 2, 3, 4, 5, 6, 7, 8, 9]

13. Adding values to specific index in
Array
• To insert an item into the array at a specified index,
call the array’s insert(at:) method.
• Example:
var arr: [Int] = [1,3,7,10]
insert(5, at: 2)
insert(9, at: 4)
print(arr)
Result
[1, 3, 5, 7, 9, 10]

14. Removing values from Array
• To remove an item from a specific index call the
remove(at:) method.
• Example:
var arr: [Int] = [1,2,3,4,5]
arr.remove(at: 2)
print(arr)
Result
[1, 2, 4, 5]

15. Mutable Vs Immutable
• To declare a mutable variable or array var
keyward is used.
• To declare a immutable variable or array let
keyward is used.
• Example:
var arr: [Int] = [1,2,3,4,5] // mutable array
let arr: [Int] = [1,2,3,4,5] // immutable array

16. Any keyword
• To declare an array of any type of instance/value
Any keyword is used.
• Example:
var a: [Any] = [ ]
a.append(9)
a.append("to")
a.append(11)
• Example:
var a = [1,2,3,4,"apple","car"] as Any
print(a)

17. MCQs..
1. What will be the value of len?
var array1 = [1, 2, 3, 4, 5]
var array2 = array1
array2.append(6)
var len = array1.count
a) 4
b) 5
c) 6
d) None of these

18. MCQs..
1. What will be the value of len?
var array1 = [1, 2, 3, 4, 5]
var array2 = array1
array2.append(6)
var len = array1.count
a) 4
b) 5
c) 6
d) None of these

19. MCQs..
2. What will be the value of result?
let op1: Int = 10
let op2: UInt = 20
let op3: Double = 30.55
var result = op1 + Double(op2) + op3
a) 60
b) 60.55
c) Error
d) None of these

20. MCQs..
2. What will be the value of result?
let op1: Int = 10
let op2: UInt = 20
let op3: Double = 30.55
var result = op1 + Double(op2) + op3
a) 60
b) 60.55
c) Error
d) None of these

21. MCQs..
3. What will be the value of result?
let op1: Double = 10.20
var result:Double = 20.50 + op1
a) 30
b) 30.7
c) Error
d) None of these

22. MCQs..
3. What will be the value of result?
let op1: Double = 10.20
var result:Double = 20.50 + op1
a) 30
b) 30.7
c) Error
d) None of these

23. Questions
1. Write a program to print a maximum number from
an array.
2. Write a program to print the odd numbers from an
array.
3. Write a program to sum the positive elements of
array as well as negative elements of array.

24. Questions
1. Write a program to print a maximum number from
an array.
var listOfNumbers = [1, 2, 3, 10, 100]
var maxVal = listOfNumbers[0]
for number in listOfNumbers {
if maxVal < number {
maxVal = number
}
}
print(maxVal)

25. Questions
2. Write a program to print the odd numbers from an
array.
var listOfNumbers = [1, 2, 3, 10, 100]
for number in listOfNumbers {
if number % 2 != 0 {
print(number)
}
}

26. Questions
3. Write a program to sum the positive elements of
array as well as negative elements of array.
var listOfNumbers = [1, -2, 3, -6 , 20]
var sumPos = 0 ,sumNeg = 0
for number in listOfNumbers {
if number>0
{ sumPos += number }
else
{ sumNeg += number }
}
print(sumPos)
print(sumNeg)