how to read data into object array in Swift 4 - swift

Question

class Employee{
var id:Int
var name:String
var salary:Int
init(){
self.id=0
self.name=""
self.salary=0
}
func getInfo(){
self.name=readLine()!
self.id=Int(readLine()!)!
self.salary=Int(readLine()!)!
}
}
var count=0
var flag="y"
var empData:[Employee]=[]
repeat{
count+=1
empData[count]=Employee()
empData[count].getInfo()
flag=readLine()!
}while(flag=="y") `
I have a class Employee with properties id , nam and salary. The function getInfo() is used to get information from user. I want to read data until the flag!="y" . I am getting index out of range error.
What is the right way of inputting data? Can we index the objects ?

Answer 1

You need to append to your array to make it increase in size. Replace
empData[count]=Employee()
with
empData.append(Employee())
to avoid index out of range error
Update
To make your code a little less horrible I would do
repeat {
var employee = Employee()
employee.getInfo()
empData.append(employee)
flag=readLine()!
}while( flag == "y" )

Answer 2

The subscript operator cannot be used to add elements to an array index which doesn't exist yet. You either need to initialize the array with an element count if you know at the time of initialization how many elements your array will have or use the append operator to add new elements to the array after the last index.
You don't even need the count variable, as you can simply access empData.last safely after calling append and adding a new Employee to the Array.
var flag="y"
var empData:[Employee]=[]
repeat {
empData.append(Employee())
empData.last!.getInfo()
flag=readLine()!
} while(flag=="y")
I would advise you to seriously reconsider your implementation as it is really unsafe at the moment. You are not validating user input in any way, hence your getInfo function can easily cause runtime errors if the user input is not in the expected form. Moreover, creating an empty initializer for Employee doesn't make sense, you could simply create a failable initializer, where you read the input and if the input is not of the correct form, make the initializer return nil.
class Employee{
let id:Int
let name:String
let salary:Int
init?(){
guard let name = readLine() else { return nil }
self.name = name
guard let idString = readLine(), let id = Int(idString) else { return nil }
self.id = id
guard let salaryString = readLine(), let salary = Int(salaryString) else { return nil}
self.salary = salary
}
}
var flag="y"
var empData:[Employee]=[]
repeat {
if let employee = Employee() {
empData.append(employee)
} else {
// Display error message to the user
}
flag=readLine() ?? ""
} while(flag=="y")