Question

CODE MUST BE WRITTEN IN SWIFT programming language

Write a function that takes in two positive integers and prints every prime number between (and including) them

Sample Input:

prime(from: 0, to: 100)

Sample Output:

[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]

Answer 1

The code in Swift for printing every prime number between two integers is given below:

func prime(from: Int, to: Int)

{

var new_from = from

if(from < 3)

{

new_from = 3

print(2, terminator:", ")

}

for i in new_from...to

{

var flag = 0

for j in 2..<i

{

if i%j == 0

{

flag = 1

break

}

}

if flag==0

{

print(i, terminator:", ")

}

}

}

prime(from: 0, to: 100)

The function "prime" takes two integer arguments "to" and "from" and returns nothing. Since in Swift, we cannot change the value of the function parameters, we take a new variable named "new_from" initialized to the parameter "from". If the value of "from" is less than 3, then we initialize the "new_from" variable to 3 and print 2, since 2 is the only prime number less than 3.

Now, a for loop is used from the variable "new_from" to the variable "to. It takes every integer in between the two values (including the two values) and checks whether the integer is prime or not. If it is prime, it is being printed on the screen, else the loop continues to the next value.

The variable "flag" is used as an indicator to tell whether the control entered the "if" block inside the second "for" loop. If the control entered the "if" block, it means that the integer is divisible by some other integer (other than 1 of course) and the value of flag changes to 1. Now, if the value of flag is 0, it means that the control never entered the loop and hence the number is prime and we need to print it.

This is how the above code works.

The screenshot of the code is:

The screenshot of the output is:

Hope it helped. If you have any doubts or queries, please feel free to ask in the comments section. If it helped in any way, please consider giving a thumbs up.