Comma (,) and Diamond ()

, or : Separator

→full documentation

Separates statements in blocks, programs, and arrays. Characters , and are interchangeable with each other and with newline.

↗️
    a  3 ,  b  2
2

    1  2 , 3
3

    1 , 2  3
⟨ 1 2 3 ⟩

    {1  2  3}
3