Multiple right if-conditions Swift

Question

pretty simple question, hard solution, at least for me. How I can do the code of an if and else if statement when the conditions are both time right? like I do a variable x and y and I check if x is 5 then it says something but it says something else when y is 5 either, now the point is what if both are 5? bc after one if statement it skips the other if/else if. thanks for ur solutions!

Answer 1

Swift actually has a very powerful switch statement that you can use to check the value of multiple variables. Consider this code:

var x: Int = 3
var y: Int = 5

switch (x, y) {
case (1, 4):
    print("x == 1 and y == 4")
case (3, 5):
    print("x == 3 and y == 5")
case (5, 5):
    print("x and y are both 5")
case (5, let y) where y > 5:
    print("x == 5. Y > 5")
case (5, _):
    print("x == 5. y == some value we didn't test for.")
case (_, 5):
    print("y == 5. x == some value we didn't test for.")
default:
    print("Dunno")
}

It works by combining multiple values into a tuple, and then switching on the tuple. The cases inside the switch statement can do all kinds of different tests on the values of the tuple.

That code prints:

x == 3 and y == 5

With the values I assigned to it. The "_" bit means "don't care" for that part of the tuple. The "let y" means "Take the second value in the switch statement and assign it to a local variable y that only exists in this case." You can then add a "where" clause that lets you do more complex tests, like my "where y > 5" example.

Edit:

As Jessy pointed out in their comment, binding a value to y with let y in my case (5, let y) where y > 5: example is pointless, since the switch statement is already operating on a variable named y. It would work just as well as case (5, _) where y > 5: in that particular example.

However, if the switch statement was a switch on constant values (e.g. switch (x, 7)) or on a tuple variable:

let aTuple = (5,7)
switch aTuple {
   case (5, let y) where y > 5:
...

Then binding the second value to a variable would be useful.