Callback functions in TypeScript

For callbacks functions, you can also specify the parameter type and return type. See the example:

function make(num: number, func: (num: number) => number): number {
	return func(num);
}

Let's call our function with one callback:

make(3, function(num: number): number {
	return num ** 2;
});

And now with another callback:

make(3, function(num: number): number {
	return num ** 3;
});

Tell me what the result of running the following code will be:

type Func = (num: number) => number;

function make(arr: number[], func: Func): number[] {
	return arr.map(function(elem: number) {
		return func(elem);
	});
}

let res: number[] = make([1, 2, 3], function(num: number): number {
	return num ** 2;
});

console.log(res);

Find and correct the errors in the following code:

type Func = (num: number) => number;

function make(arr: number, func: Func): number {
	let sum = 0;
	
	for (let elem of arr) {
		sum += func(elem);
	}
	
	return sum;
}

let res: number[] = make([1, 2, 3], function(num): string {
	return num ** 2;
});

console.log(res);