I have a problem with conditions in Control Flow.

Question

I have a fixed array is: let terms: [Int] = [1,2,3,4,5,6,7,8,9,10,11,12,13,15,18,24,36].
I wrote a function with parameter is an Int. I want to check the parameter that will map with multiple condition in there function. That's my function:

"func configTerms(with term: Int) -> [String] {

termConditions = ["A"]

switch term {

case 1...:

termConditions.append("B")

case 2...:

termConditions.append("C")

case 6... where term % 3 == 0:

termConditions.append("D")

case 12... where term % 6 == 0:

termConditions.append("E")

case 24... where term % 12 == 0:

termConditions.append("F")

default:

print("Can't match any value")

}

return termConditions

}"
I can resolve it by using "if...else" control flow but the last condition will be very long and complex.

I used "switch...case" control flow but it couldn't return result that i wanted.

Example: When input was 12, function only returned ["A","B"] instead of ["A","B","C","D","E"]

Everytime the condition matched, the "switch...case" breaked out and only returned ["A","B"].
I used fallthrough but it didn't check the next condition and executed next expression.
How can i continue using "switch...case" in this case without using "if...else"?

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Posted by

Ngocson

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Answer 1

That's a little bit different than I guessed. I think you have no need to nest `if`s.

func configTerms2(with term: Int) -> [String] {
    var termConditions = ["A"]
    
    if case 1... = term {
        termConditions.append("B")
    }
    if case 2... = term {
        termConditions.append("C")
    }
    if case 6... = term, term % 3 == 0 {
        termConditions.append("D")
    }
    if case 12... = term, term % 6 == 0 {
        termConditions.append("E")
    }
    if case 24... = term, term % 12 == 0 {
        termConditions.append("F")
    }
    return termConditions
}

Posted by

OOPer

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Answer 2

How can i continue using "switch...case" in this case without using "if...else"?

The answer is simple. You cannot. Use `if`. `switch`-statement is intended to match only one case. It may not be what you want.

Posted by

OOPer

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Answer 3

I've resolved this problem. It's seem to be quite ugly but the result is alway true. Below is my code:

func configTerms(with term: Int) -> [String] {

termConditions = ["A"]

switch term {

case 24... where term % 12 == 0:

termConditions.append("B")

termConditions.append("C")

termConditions.append("D")

termConditions.append("E")

termConditions.append("F")

case 12... where term % 6 == 0:

termConditions.append("B")

termConditions.append("C")

termConditions.append("D")

termConditions.append("E")

case 6... where term % 3 == 0:

termConditions.append("B")

termConditions.append("C")

termConditions.append("D")

case 2...:

termConditions.append("B")

termConditions.append("C")

case 1...:

termConditions.append("B")

default:

print("Can't match any value")

}

return termConditions

}

If u have better answer. Plese let me know. Thanks for reply!

Posted by

Ngocson

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Answer 4

If u have better answer. Plese let me know.

For me, using-`if` seems to be super better than using such an ugly `switch` forcefully. You know how you can write it in `if`s.

Posted by

OOPer

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Answer 5

Yes. i know and i tried. It's a nested control flow with 5 grades. Below is my code in "if...else":

if term >= 1{

termConditions.append("B")

if term >= 2{

termConditions.append("C")

if term >= 6 && term % 3 == 0 {

termConditions.append("D")

if term >= 12 && term % 6 == 0 {

termConditions.append("E")

if term >= 24 && term % 12 == 0{

termConditions.append("F")

}

return termConditions

In near future, if i add some conditions in it, it'll be more and more complex, so hard to maintain.
Thanks for your advice. I'll think more to take the best choice.

Posted by

Ngocson

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Answer 6

That's a little bit different than I guessed. I think you have no need to nest `if`s.

func configTerms2(with term: Int) -> [String] {
    var termConditions = ["A"]
    
    if case 1... = term {
        termConditions.append("B")
    }
    if case 2... = term {
        termConditions.append("C")
    }
    if case 6... = term, term % 3 == 0 {
        termConditions.append("D")
    }
    if case 12... = term, term % 6 == 0 {
        termConditions.append("E")
    }
    if case 24... = term, term % 12 == 0 {
        termConditions.append("F")
    }
    return termConditions
}

Posted by

OOPer

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Answer 7

Thank you so so much. I've checked and your answer is the best clearly 😀

Posted by

Ngocson

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I have a problem with conditions in Control Flow.

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