getValue with type inference in typescript

getValue.ts

const getValue = <TObj, Tkey extends keyof TObj> (obj: TObj, key: Tkey) => obj[key]

const result = getValue({a: "hello", b: 2, c: true}, "a")

console.log(result) // defined as string

const result2 = getValue({a: "hello", b: 2, c: true}, "b")

console.log(result2) // defined as number

const result3 = getValue({a: "hello", b: 2, c: true}, "c")

console.log(result3) // defined as boolean