array as a function argument

This is a syntactic error. Here is the amended code:

function arrayCounter(ar){
        if (typeof ar === 'undefined' || typeof ar === 'number' || typeof ar ==='string') {
            return 0;
        } else {
          return ar.length;
        }
}

You wrote 'Number' and 'String' instead of 'number' and 'string'. When checking the types, its all in lower case!

Hello!

Post the code you're using for us to be able to help you. From what I see it, if you just pass an array variable as an argument to a function (that takes a parameter), it will hold that array value in the parameter variable. So for example if the main variable was john1 and the parameter was john2 in a join() function, you'd do this:

Call join() with john1 as an argument so join(john1). This will make john2 a replica of john1 i.e. an array. Just use john2(1) or any other value to access the array.

Thanks!

this is my challange

Around line 17, create a function named 'arrayCounter' that takes in a parameter which is an array. The function must return the length of an array passed in or 0 if a 'string', 'number' or 'undefined' value is passed in.

and this is my code

<script>
function arrayCounter(array){ if(typeof array==='undefined' || typeof array==='Number' || typeof array ==='String'){ return 0; } return array.length; } arrayCounter();

</script>

<script>

  function arrayCounter(array){
    if(typeof array==='undefined' || typeof array==='Number' || typeof array ==='String'){
        return 0;
    }
    return array.length;
  }
  arrayCounter();

</script>

it worked, thanks for your help.