if integer is greater than x but less than y (Swift)

Question

I was wondering if there is any smooth way of checking the value of an integer in a range in swift.

I have an integer that can be any number between 0 and 1000

I want to write an if statement for "if the integer is between 300 and 700 - do this and if its any other number - do something else"

I could write:

if integer > 300 {
    if integer < 700 {
      //do something else1
    }
    //do something
} else {
    // do something else2

}

But I want to minimize the amount of code to write since "do something else1" and "do something else2" are supposed to be the same

It doesn't seem that you can write :

if 300 < integer < 700 {

} else {

}

I tried using

if integer == 300..<700 {
}

but that didn't work either. Anybody got a suggestion?

You should really read the documentation: developer.apple.com/library/prerelease/ios/documentation/Swift/… — Hunter McMillen
– Hunter McMillen, Commented Apr 4, 2015 at 13:26
"I tried using "if integer == 300..<700" – The given answer shows the straight forward solution, but something like that is possible, compare Can I use the range operator with if statement in Swift?. — Martin R
– Martin R, Commented Apr 4, 2015 at 13:28
Thanks for pointing that out! So the shortest way is to use if 300 ... 700 ~= integer { // do something } else { // do something else } — William Larson
– William Larson, Commented Apr 4, 2015 at 14:14

CrApHeR · Accepted Answer · 2015-04-04 13:25:43Z

13

Did you try this?

if integer > 300 && integer < 700 {
    // do something
} else {
    // do something else               
}

Hope this helps

edited Apr 4, 2015 at 13:25

answered Apr 4, 2015 at 13:24

CrApHeR

2,6654 gold badges29 silver badges43 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

William Larson Over a year ago

Thanks, that does work! I thought there might have been an even shorter way of writing it without repeating with && and "integer" but this might be the best way. Thank you

William Larson Over a year ago

Actually I did find a shorter way that Martin R pointed to You can write: if 300 ... 700 ~= integer { }

Alex Brown Over a year ago

William +1 but use the half open operator!

Airspeed Velocity · Accepted Answer · 2015-04-04 14:10:26Z

10

There is a type, HalfOpenInterval, that can be constructed with ... and that has a .contains method:

if (301..<700).contains(integer) {
    // etc.
}

Note, 301..<700 on its own will create a Range, which doesn’t have a contains function, but Swift’s type inference will see that you’re calling a method that only HalfOpenInterval has, and so picks that particular overload.

I mention this just because if you want to store the interval as a variable instead of using it in-line, you need to specify:

let interval = 301..<700 as HalfOpenInterval
if interval.contains(integer) {
  // etc.
}

answered Apr 4, 2015 at 14:10

Airspeed Velocity

41.1k8 gold badges116 silver badges119 bronze badges

4 Comments

Martin R Over a year ago

Interestingly, with Xcode 6.3 in optimized mode, this also gives the same "optimal" assembly code as if integer > 300 && integer < 700 or if 300 ... 700 ~= integer which I just added to stackoverflow.com/a/24893494/1187415.

Airspeed Velocity Over a year ago

Yeah apparently all the standard library code can be inlined (and the swift compiler is very keen to inline with -O)

Alex Brown Over a year ago

And as Willian Larson points out, the contains operator can be used for shorter syntax, in if 300..<700 ~= integer {

Airspeed Velocity Over a year ago

I’m not sure that’s really the intended use of the ~= operator, I see that more as the underlying mechanism for switch rather than something supposed to be used stand-alone. .contains signals intent more clearly IMHO.

Collectives™ on Stack Overflow

if integer is greater than x but less than y (Swift)

2 Answers 2

3 Comments

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related