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Ben Masel
2,004 PointsCan't complete these tasks!
Task 1 i can't complete, I have tried many things. If you want me to try again i will but please tell me if it uses Unary Operators, Binary Operators or both. It also says on swift 3 "++" and "--" will be removed. What operator will replace them?
// Enter your code below
var initialScore = 8
initialScore = initialScore + 1
let totalScore = initialScore
4 Answers
Jennifer Nordell
Treehouse TeacherBenjamin Masel Actually, I just had a thought. Let me show you the equivalent code without using an increment operator. Maybe it will clarify things.
This:
var initialScore = 8
let totalScore = initialScore++
is equivalent to:
var initialScore = 8
let totalScore = initialScore // totalScore is now 8
initialScore = initialScore + 1 // initialScore is now 9
And this:
var initialScore = 8
let totalScore = ++initialScore
is equivalent to:
var initialScore = 8
initialScore = initialScore + 1 //initialScore is now equal to 9
let totalScore = initialScore //totalScore is now equal to 9
Again, the main idea here is the order in which the assignment and the increments happen. Hope this helps
Jennifer Nordell
Treehouse TeacherAs I understand it, in Swift 3 you will be using code like x += 1 instead of x++. This challenge requires the use of a unary operator.
Now, let's look at step one:
var initialScore = 8
let totalScore = ++initialScore
This sets initalScore to 8. Then it increments initialScore to 9 and assigns 9 back into totalScore. At this point totalScore and initialScore both hold the value of 9.
But if we did it this way:
var initialScore = 8
let totalScore = initialScore++
This would first assign initalScore (which has a value of 8) into totalScore and then it would increment initialScore to 9. The result would then be that we would have 8 in totalScore and 9 in initialScore. Hope this helps!
Ben Masel
2,004 PointsThank You!
Ben Masel
2,004 PointsIt helped so MUCH!
Ben Masel
2,004 PointsSo the "++" makes the constant in this case "totalScore = totalScore + 1" which is "totalScore = ++totalScore"? and if it was "totalScore = totalScore++" it would make totalScore = initialScore but initialScore won't equal totalScore?
Jennifer Nordell
Treehouse TeacherBenjamin Masel there is no code that increments totalScore. What they are trying to illustrate to you here is the difference between putting the ++ before the initalScore and putting it after. Let's look at it one more time.
If we have this:
var initialScore = 8
let totalScore = initialScore++
In this case, initialScore starts at 8. Now we have an empty constant named totalScore. It has no value. We assign initalScore back into totalScore. At this point, totalScore is is now equal to 8. But after we do the assignment we're going to increment initialScore. This will mean that initialScore now has a value of 9, but totalScore still only has a value of 8.
If we do this:
var initialScore = 8
let totalScore = ++initialScore
Now this starts off the same. initialScore has a value of 8 and totalScore has no value. But here's the big thing. We do the increment before we do the assignment. So now we increment initialScore to 9 and then we assign it back into totalScore. Now initalScore and totalScore both have a value of 9.
Keep in mind though, that this is being deprecated. Also, there are rather few scenarios where this matters that much. But they clearly want you to be familiar with it.
Hope this helps!