Hi Jon.

I try spending sometime reading simple open source projects. Came across yours and I would like to suggest something. What I have noticed is that in line number 22, the program returns first[0] else it returns the variable first as an entire array.

Would you consider maybe returning this instead:

  if (+num === 1 || num == null) {
    return [first[0]];
  }
  return first;

So both return types are arrays. What are your thoughts on that? Otherwise this is a nice simple program and I like it!

function arrayFirst(array, value = 1) {
if (!Array.isArray(array)) throw new TypeError('Please input right Array')
if(typeof value !=== 'number') throw new TypeError(‘please input right value')
if (array.length === 0) return null
return +value === 1 ? array[0] : array.slice(0, value)
}

const newArray = arrayFirst(['a', 'b', 'c', 'd', 'e', 'f']);