Day 1: 'Infix modifier is required on "filter" in "kotlin.collections"'

1

I am just getting started with Kotlin and following the walkthroughs. One of them is this example:

fun main(args : Array<String>) {
    args filter {true} forEach {print ("Hello, $it!")}
}

very pretty, but IntelliJ gives me red squigglies on the filter and forEach symbols and complains that infix modifiers are required on “kotlin.collections.” I googled around and tried a bunch of hacks, but don’t see a way to fix this.

EDIT:

Interspersing dots, fixes it, of course

args.filter {true}.forEach {print ("Hello, $it!")

but I still wonder whether and how the infix syntax from the walkthroughs is available

2

May be those walkthroughs are outdated? Those methods don’t have infix modifier, you can’t call them in infix position.

1 Like
3

thanks. looks like this is the case. I’m ok with dots.

4

I’m still having this issue.

5

This is a three-year-old topic where OP didn’t use proper syntax to call methods by leaving out the required dots, “.”, in his code.

It seems like the original poster was incorrectly copying a walkthrough, or perhaps the walkthrough was incorrect.

@Tyluur, what is your issue? Which lines of code throw your error? What solutions have you already tried? When you say “this issue” do you mean you get a similar error message to OP? Can you narrow it down or at least describe what you mean by “this issue”?

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