Typescript Generic Function
function makePair<
F extends number | string,
S extends boolean | F
>()
- Generic function only able to pass number, string
function makeState<S extends number | string>()
- Generic function default type as number
function makeState<S extends number | string = number>()
- Generic function with multiple type parameters
```typescript
// makeState() has 1 type parameter
function makeState
() // makePair() has 2 type parameters function makePair<F, S>()
// The second parameter S must be either // boolean or whatever was specified for F function makePair< F extends number | string, S extends boolean | F >()
### Generic classes
```ts
function makeState<S>() {
let state: S
function getState() {
return state
}
function setState(x: S) {
state = x
}
return { getState, setState }
}
// Pass a type parameter on initialization
const numState = new State<number>()
Common Used Abbreviation
- T (for “T”ype)
- E (for “E”lement)
- K (for “K”ey)
- V (for “V”alue)
- S (for “S”tate)
