type T1 = 1 | 'b' & string | number // "b" | number
type T2 = 1 | 2 & 1 | 3 // 1 | 3
I'm new to TS. Can someone tell me why it's "b" | number and 1 | 3 and what's going on here?
& has higher precedence than |Thus your code is interpreted as:
type T1 = 1 | ('b' & string) | number
type T2 = 1 | (2 & 1) | 3
in which case "b" | number and 1 | 3 make sense.
If you add parenthesis it will work the way you have in mind:
type T1 = (1 | 'b') & (string | number) // 1 | "b"
type T2 = (1 | 2) & (1 | 3) // 1