Generic Function in TypeScript

In the previous lessons, we made an identity function that took parameters of a generic type. Now we will learn how to describe the type of such a function and create generic interfaces.

A function of a generic type can also be written as an arrow function. Let's declare a variable func, which will have the type of a generic function:

function myFunc <T> (data: T): T {
	return data;
}

let func: <T> (data: T) => T = myFunc;

You can also specify another symbol for the generic type of such a variable. The main thing is to ensure that the type names do not conflict:

function myFunc <T> (data: T): T {
	return data;
}

let func: <U> (data: U) => U = myFunc;

A generic type can be written by enclosing the call signature and the function type in curly braces:

function myFunc < T > (data: T): T {
	return data;
}

let func: {<U> (data: U): U} = myFunc;

Write a function to determine the length of a generic array in the variants described in this lesson.