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.

I worked this out to be:

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

Very confused, still. When did we learn the use of ||? Why would we learn typeOf if what we really need here is instanceOf? Else was not mentioned in this lesson, either.

Jim Hoskins may be worth updating this video, or changing the challenge a bit!

This code passed the challenge.

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

This is kind of a difficult lesson to follow along with.

Yea where did || come from? Can any body show us how this is done using what we've been taught up until this point instead of using instanceOf or ||

I went with the instanceof operator to see if the argument was an array. Took me at least 20 minutes of googling to figure out a way to get this done. @Zen, you're totally right, feels AMAZING to figure it out by yourself.

function arrayCounter(array) {
     if (array instanceof Array === true)
     {
     return array.length;
     }
     else
     {
     return 0;
     }
}

Can someone better define to me what instanceof does?

What challenge are you on?

Stage 5 functions Challege 1 of 1, ah I added the bracket and progress; now it says "wrong value returned from 'arrayCounter'("string")' it should be 0.

Ah ok, more progress, now I've got function arrayCounter(array) { if (typeof array === 'string', 'number', 'undefined') { return 0; } return array.length; }

Bummer! If I pass in an array in to 'arrayCounter' of '1,2,3' I get 0 and not the number 3.

I'm lost, when I type "1, 2 ,3" it into the console I get a return value of 3?

Ok I got it! Thanks heaps pal, you're a legend.

Can someone please help me with this as well? What I have so far:

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

Tiffany, I was just stuck on this as well.

Make sure you double check what your parameter ought to be called.

Also, take a look at Mozilla's developer tools (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof) and see if this helps.

They are looking for the function to be able to return arrays only (or, almost only). So, it may be easier to think about this in terms of negation rather than equality (think !== rather than ===).

Sean Templeton's question "What exactly are you comparing?" is what helped me with this, although I'm not sure I went the way he was leading.

Hope this helps!

Ok I have no idea what I am doing wrong. I'm getting the message "You're not checking if 'undefined' is being passed in"

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

If I change to this

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

I get this message: If I pass in an array in to 'arrayCounter' of '1,2,3' I get 0 and not the number 3.

Doesn't it feel so gnarly when you figure it out yourself? Good job!

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.

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

Spent forever trying to use typeof for array, but an array is an object, so the function never worked right. Switched to using instanceof and it worked...

function arrayCounter (x) {
    if (x instanceof Array) {
        return x.length;
    } else {
        return 0;
    } 
}

OMG... Took me atleast 30 minutes but!!!!

function arrayCounter (myArray) { if (typeof myArray === 'string' ||typeof myArray === 'number' ||typeof myArray === 'undefined') { return 0; } return myArray.length; } //I got it!

Took a little bit but got it: function arrayCounter(myArray) { if(typeof myArray==='string'){ return 0; } if(typeof myArray==='number'){ return 0; } if(typeof myArray==='undefined'){ return 0; } else { return myArray.length;} } Hope this helps

Hey guys,

This is the method i used, and seemed to have worked.

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

but after solving the problem, in order to write clean and readable code, i should have done it this way.

      function arrayCounter(xyz){
         if (typeof xyz === 'undefined' || typeof xyz === 'number' || typeof xyz === 'string'){
              return 0;
         }

             else{
                return xyz.length;
             }
      }

Both should anyways work, but it is always best to follow best practices.

Here's the long way:

 function arrayCounter(myArray) {
   if (typeof myArray === 'string') {
    return 0;

   }else if (typeof myArray === 'number') {
    return 0;

   }else if (typeof myArray === 'undefined') {
    return 0;

   }else {
    return myArray.length;
   }
}

Great discussion so far...

I understand how the most recent answer works, but what if "typeof myArray === boolean"? That would not be a string, a number, or undefined, so wouldn't the function try to return the code that is in the else statement (which would lead to an error because it is trying to determining the length of a boolean)?

Thanks, Mike

Hey i just tried this code and works pretty smooth.

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

Another option :

function arrayCounter(x){
        if (Array.isArray(x) === true){
          return x.length;
        }else{
          return 0;
        }
      }