When I read Julia source codes, sometimes the type parameterization writes `where T`

, sometimes `where {T}`

. Are they different or the same?

# `where T` vs `where {T}`

**pochoi**#1

**foobar_lv2**#2

They are the same. `where {T1, T2, T3}`

is the same as `where T3 where T2 where T1`

is the same as `where {T3} where {T2} where {T1}`

.

Some people, me included, prefer to always put in the brackets even if unneeded, in order to aid the eye at scanning for type parameters. But that is a matter of taste. There probably is some piece of history here that I don’t know.

not much history beyond the “discovery” that writing

`where {T1, T2, T3}`

leads to nicer visuals than `where T3 where T2 where T1`

there are occasions when the long form is helpful, where one or more of the Ti are compound or triangular locally