One way to create a function with a generic type argument and a default value of null is:
function myFunction<T = null>(param: T = null): T {
// Function code here
return param;
}
In this example, the T
parameter is a generic type argument with a default value of null
. The param
parameter is of type T
and has a default value of null
. The function code can use T
as needed.
Another way to implement the same thing in TypeScript is by using Partial<T>
:
function myFunction<T>(param: Partial<T> = {}): T {
// Function code here
return param as T;
}
This implementation allows the param
argument to be an object that is a partial implementation of the T
interface. The default value is an empty object {}
which satisfies the Partial<T>
type. The function code can use T
as needed, and the return value is cast to type T
.
Asked: 2021-08-13 11:00:00 +0000
Seen: 11 times
Last updated: Jan 20 '22