After defining the constant MODE with specific values, I noticed something interesting:
const MODE = {
NONE: 0 as 0,
COMPLETED: 1 as 1,
DELETED: 2 as 2
} as const
// In a CreateReactApp project, enums aren't available
It became apparent that these types would remain fixed upon assignment.
let mode = MODE.NONE
let someNumber = 5
The type of 'mode' is set to 0, while 'someNumber' retains its number identity. If I transfer a final value into a let variable, it typically indicates a desire for modification rather than preservation.
To address this issue, you can explicitly define the variable type:
let mode: number = MODE.NONE // or use a more specific type like typeof MODE[keyof typeof MODE]
However, I'm curious about the reasoning behind preserving literal types in such scenarios. When is it beneficial to maintain a literal type after assigning a value to a non-readonly variable or property?