Why do parameters in a Helper Function need to be reiterated?

JavaScript
1

I’m examing this code and am trying to figure out why the parameters of monitorCount need to be reiterated in the costOfMonitors function? The return of monitorCount is rows * columns.

Wouldn’t you then be able to simply make the return of costOfMonitors:

return monitorCount * 200;

because monitorCount has already been returned/determined with:

function monitorCount(rows, columns) {
  return rows * columns;

Here’s all the code:

function monitorCount(rows, columns) {
  return rows * columns;
}
function costOfMonitors(rows, columns)
{
  return monitorCount(rows, columns) * 200;
}

const totalCost = costOfMonitors(5, 4);
console.log(totalCost);
2

Hello @El_Escandalo :grinning:

monitorCount function has two parameters so to take it’s return value you have to call monitorCount function with arguments otherwise it won’t be return value(rows*columns) , it will return NaN.

You can use costOfMonitors function only but here is two different functions so in my opinion it’s better to divide this code in two functions because it will give a better understanding.

1 Like
3

Thanks but aren’t the arguments called already in the 2nd line of code? Does a return not “hold” the values?

function monitorCount(rows, columns) {
  return rows * columns;
}
4

You can use costOfMonitors function only but here is two different functions so in my opinion it’s better to divide this code in two functions because it will give a better understanding.

1 Like
5

To make use of that return value, you’ll need to give it some data to work with. That’s how the monitorCount function is defined.

Just because they happen to have the same parameter names doesn’t mean they “share” them and you can omit them when calling monitorCount.

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6

@dev-313 is correct. If you return monitorCount without parameters it is going to run that function without the parameters it needs, so think of it as calling monitorCount() with nothing being passed into it.

2 Likes
7

@kevcomedia Thanks- but if they don’t “share” the parameters, then at what point is monitor count assigned an argument? Am I right in thinking that const totalCost = costOfMonitors(5, 4); assigns totalCost the function of costOfMonitors with the arguments of 5, 4, but where is monitorCount assigned an argument, if the variables rows, columns are not shared?

8

The rows and columns values from costOfMonitors are explicitly passed to monitorCount right at the return statement of costOfMonitors.

1 Like