can someone explain this while loop to me

Hello Alexander:

A while loop will continue working until the condition given to it becomes false. So in this code you want the loop to go over some characters and stop at the last character.

Your code:

var str = "Hola, Rob"

var i = 1

while (i < 8) {
     print(Array(str.characters)[i])
     i++   

// If i is less than 8 print a character and repeat until it becomes false
// 7 is less than 8, but 8 is not less than 8, so loop stops at 7.
}

Hola, Rob has 9 characters, in which the space also counts as a character. Arrays have index numbers that start at 0.

• H = 0,
• O = 1
• L = 2
• A = 3
• , = 4
• (Space) = 5 ,
• R = 6,
• O = 7
• B = 8

So the letter H is 0 by index, and the last letter b is 8 by index.

In your code you have a variable called i that has a value of 1, therefore if you start the loop at 1, then the first letter printed would be o.

When you instruct the loop i < 8 (While i is less than 8 print a character), but when it gets to 7 then it stops there, because 8 is not less than 8, therefore it becomes false, and then loop stops shy of one character.So in order to print those 2 characters that are not printing we have to do two things.

• 1) Start the count at 0
• 2) End the count at 9

var str = "Hola, Rob"

var i = 0

while (i < 9) {
    print(Array(str.characters)[i])
    i++
}

I hope this helps you understand a bit better.

I encourage you to use the votes up or down and best answer markers to help other students find good answers.

Good luck :)