```val str = "hey" when (val line = str) { "a...

# announcements

[karelpeeters]

val str = "hey"

when (val line = str) {
    "abc" -> println("abc")
    line.startsWith("h") -> println("starts with h")
}

Any reason this doesn't work? It says Incompatible type: Boolean and String on the .startsWith part.

[MrNiamh]

It's comparing line with line.startsWith("h"), so "hey" and true/false

[karelpeeters]

Of course 🤦‍♂️

[Spike Baylor]

for learning purposes, IS there a way to do what Karel is trying to do here?

[karelpeeters]

I think you have to resort to doing something like this unfortunately:

val str = "hey"

when {
    str == "abc" -> println("abc")
    str.startsWith("h") -> println("starts with h")
}

[Spike Baylor]

ok thats what i was thinking. Not the end of the world

[marstran]

What would this print if it were allowed? 🙂

val bool = false
when (val b = bool) {
  b == true -> println(1)
  else -> println(2)
}

Here, b is equal to the result of b == true, but b == true would be false. So the result would be ambigous.

[karelpeeters]

Yeah of course, seems like I wasn't thinking straight.

[marstran]

b == true -> println(1) would both print and not print at the same time 😄 Schrödinger code

[Hamza]

val str = "hey"

when (val line = str) {
"abc" -> println("abc")
lstartsWith("h") -> println("starts with h")
}
Any

[Hamza]

Remove line from line.startsWith()

[karelpeeters]

That doesn't work unfortunately, that would try to call a function startsWith and compare line with the return value.

[karelpeeters]

It would be cool if we could do .startsWith("h") or something.

[Egor Trutenko]

Or we we had proper pattern-matching 🤔

[karelpeeters]

Yeah when needs some upgrades.