What does 2 in square bracket of function f[x_][2]? [closed]

There is a function which looks like f[x_][2]:= . What does 2 in square bracket mean?

• It's a nested function where 2 is one of the arguments. One could also write a function like f[x_][y_] := {x, y}, for instance. Jan 29 at 1:13
• Array[f[x_], 5] Jan 29 at 1:31
• You may also find this and this sections of my book useful. There I have briefly discussed such functions. Technically such definitions are called SubValues, and you may search for this term on this site and elsewhere, to find more information on these. Jan 29 at 11:24