switch that checks NSIndexPath's row and section

Question

I would like to set a switch statement that checks for a value if NSIndexPath. NSIndexPath is a class and it consists(among other things) of section and row (indexPath.row, indexPath.section)

this is how I would formulate an if statement to check for a row and a section at the same time:

if indexPath.section==0 && indexPath.row == 0{
//do work
}

What is swift switch translation for this?

Perhaps useful: http://stackoverflow.com/questions/30189505/missing-return-uitableviewcell. — Martin R, Mar 11 '16 at 17:18

matt · Accepted Answer · 2016-03-11T18:30:57.037

34

One way (this works because NSIndexPaths themselves are equatable):

switch indexPath {
case NSIndexPath(forRow: 0, inSection: 0) : // do something
// other possible cases
default : break
}

Or you could just test against integers, using a tuple pattern:

switch (indexPath.section, indexPath.row) {
case (0,0): // do something
// other cases
default : break
}

Another trick is to use switch true and the same condition you're already using:

switch true {
case indexPath.row == 0 && indexPath.section == 0 : // do something
// other cases
default : break
}

Personally, I would use nested switch statements where we test against indexPath.section on the outside and indexPath.row on the inside.

switch indexPath.section {
case 0:
    switch indexPath.row {
    case 0:
        // do something
    // other rows
    default:break
    }
// other sections (and _their_ rows)
default : break
}

edited Mar 11 '16 at 18:30

answered Mar 11 '16 at 17:05

matt

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1

I agree with your preferred nested approach, but the second could also be done as a `switch (indexPath.row, indexPath.section) { case(0,0): ...` – Martin R Mar 11 '16 at 17:16
@MartinR D'Oh! I'm, like, Mister Tuple and I still dropped the ball on that one. – matt Mar 11 '16 at 17:18
1

Second approach looks just great. Thank you! – potato Mar 11 '16 at 18:56
@matt Thanks for sweet answer – Trzy Gracje Jun 14 '18 at 09:33

heyfrank · Answer 2 · 2018-06-07T10:56:43.997

Just use IndexPathinstead of NSIndexPath and do the following:

Tested in Swift 3 and 4:

switch indexPath {
case [0,0]: 
    // Do something
case [1,3]:
    // Do something else
default: break
}

The first integer is the section, the second one is the row.

EDIT:

I just noticed that this method above isn't as powerful as the tuple matching method of matt's answer.

If you do it with a tuple, you can do something like this:

switch (indexPath.section, indexPath.row) {
case (0...3, let row):
    // this matches sections 0 to 3 and every row + gives you a row variable
case (let section, 0..<2):
    // this matches all sections but only rows 0-1
case (4, _):
    // this matches section 4 and all possible rows, but ignores the row variable
    break
default: break
}

See https://docs.swift.org/swift-book/LanguageGuide/ControlFlow.html for complete documentation of possible switch statement usages.

score 0 · Answer 3 · answered Feb 02 '20 at 14:00

An Alternative way is to combine switch with if case

switch indexPath.section {
case 0:
    if case 0 = indexPath.row {
        //do somthing
    } else if case 1 = indexPath.row  {
          //do somthing
        // other possible cases
    } else { // default
        //do somthing
    }
case 1:
// other possible cases
default:
    break
}

switch that checks NSIndexPath's row and section

3 Answers3

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