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What does first parameter `&lt;X&gt;` stand for? It always confused me..


`X` is a generic type <https://kotlinlang.org/docs/reference/generics.html>

What I was looking for is generic functions.. but I don't get the point of it.. is this ```fun &lt;T&gt; singletonList(item: T): List&lt;T&gt; { // ... }``` same as this ```fun singletonList(item: T): List&lt;T&gt; { // ... }```

what the removed param stands for? It isn't return type as return type is specified after (args):

it specifies that the function call needs to have a T parameter inferred from the context it was called from

If you leave the &lt;T&gt; out in the lines above, then it will simply say it's unknown -- by putting it there you're "declaring" it local to the function declaration

(as opposed to inheriting it from the class the function is a member of or whatever)

specifically in this case, you're specifiying a constraint:  the same type you pass as an argument is to be used for the return type

I am coming from Java World.. does this stuff exist in Java?

yes, Collections.singletonList() has a type parameter there too