what's the idiomatic way to check if 3 or 4 or eve...

# getting-started

[Karlo Lozovina]

what's the idiomatic way to check if 3 or 4 or even more variables are all the same? something like a == b == c == d ... ?

[Casey Brooks]

Not really super clean or idiomatic, but maybe something like :

val allSame = listOf(a, b, c, d).distinct().size == 1
// or
val allSame = listOf(a, b, c, d).zipWithNext().all { (first, second) -> first == second }

Otherwise, you'd have to chain the individual checks in some way (a == b && b == c etc.)

[Karlo Lozovina]

Thanks, let's stuff everything in a list and see 🙂

It's inside a hot loop, might be too slow in the end...

[dmitriy.novozhilov]

setOf(a, b, c, d).size == 1

[jwass]

I might ask why you’re trying to do this, the usage might inform the cleaner syntax. If you’ve a known value for a and you want to check that b, c and d are equal to it, then I see no problem with (a == b && a == c && a == d). It’s clear what it means, maintainable (you can remove any check without having to stitch back the chain). It’s also most efficient to execute because of short-circuiting, though that probably doesn’t matter so much in this case.

[Jacob]

sequenceOf(b, c, d).all{it == a}