I have a type
type Rating = 0 | 1 | 2 | 3 | 4 | 5 | number
Now I want to do something like this.
let myRating:Rating = 4
let rate:number = myRating as number
How can I cast my myRating into number primitive type?
It is giving me error as:
Conversion of type 'Rating' to type 'number' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.ts(2352)
I have been through this, but what I want is its reverse
Edit:
tsconfig.json
{
"compilerOptions": {
"noImplicitAny": false,
"target": "es6",
"allowJs": true,
"skipLibCheck": false,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"forceConsistentCasingInFileNames": true,
"module": "esnext",
"moduleResolution": "node",
"resolveJsonModule": true,
"isolatedModules": true,
"noEmit": true,
"jsx": "preserve",
"strict": true
},
"include": [
"src"
]
}
tsc version: 3.2.1
Try:
myRating as unknown as number
Also, remove | number from your declaration.
Explanation:
You cannot cast from a custom to a primitive without erasing the type first. unknown erases the type checking.
TS 3.8 update
now no need to cast using as, it is supported implicitly except in some cases. Where you can do type conversion as given in the accepted answer. Here is a good explanation of type conversion on the typescript.
type Rating = 0 | 1 | 2 | 3 | 4 | 5;
let myRating:Rating = 4
let rate:number = myRating;
I think it is fixed in the typescript update TS 3.5.1
type Rating = 0 | 1 | 2 | 3 | 4 | 5;
let myRating:Rating = 4
Now
let rate:number = myRating;
and
let rate:number = myRating as number;
both working fine.