If an app asks for a user's age, it may be because the app requires a user to be over a certain age to use some of the services it provides. Write a function called checkAge that takes one parameter of type String. The function should try to convert this parameter into an Int value and then check if the user is over 18 years old. If he/she is old enough, print "Welcome!", otherwise print "Sorry, but you aren't old enough to use our app." If the String parameter cannot be converted into an Int value, print "Sorry, something went wrong. Can you please re-enter your age?" Call the function and pass in userInputAge below as the single parameter. Then call the function and pass in a string that can be converted to an integer. Go back and update your function to return the age as an integer. Will your function always return a value? Make sure your return type accurately reflects this. Call the function and print the return value.
func checkage(age: String)->Int?
{
if let age_type = Int(age)
{
if age_type > 18 {
return "Welcome!"
}
else if age_type < 18 {
return"Sorry, but you aren't old enough to use our app."
}
}
else {
return "Sorry, something went wrong. Can you please re-enter your age?"
}
return age_type
}

Answer and Explanation:

Here the programming language swift is being used. There is a slight error in the program shown above:

var userInputAge=9

func checkage(age: String)->int?

{

if let age_type = Int(age)

{

if age_type > 18 {

return "Welcome!"

}

else if age_type < 18 {

return"Sorry, but you aren't old enough to use our app."

}

}

else {

return "Sorry, something went wrong. Can you please re-enter your age?"

}

return age_type

}

The program should be revised :

func checkage(age: int?)->String

{

if let age_type = Int(age)

{

if age_type > 18 {

return "Welcome!"

}

else if age_type < 18 {

return"Sorry, but you aren't old enough to use our app."

}

}

else {

return "Sorry, something went wrong. Can you please re-enter your age?"

}

return age_type

}

We call the functions :

checkage(userInputAge)

checkage("15")

Note: we revised the program for errors in the first line of the code where the int optional parameter(int?) was supposed to be used instead of the String parameter in the function. We then called the function using the userInputAge variable defined as the parameter and then we now also used a String as the parameter for calling the function the second time.

def checkage(age: "String")->int:

   if age >= 18:

       return "Welcome!"

   return "Sorry, but you aren't old enough to use our app."

for _ in iter(list,0):

   myage = int(input("Please enter your age: "))

   if myage is int(myage):

       result = checkage(myage)

       print(result)

       break

   print("Sorry, something went wrong. Enter integer value as age.")

Explanation:

The python code above lets the user input the age value for continuous comparison. If the age is an integer, it checks to know if the age is greater than 18 or not. If yes, it returns "Welcome!" else "Sorry, but you aren't old enough to use our app". But if the age is not an integer, it displays the message "Sorry, something went wrong. Can you please re-enter your age?" then prompts the user again for the age.

Note: the ': "String" ' and "->int" is for documentation purposes. They are used to describe the type of parameters (for later) and return value (the former).