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JavaScript JavaScript Foundations Functions Return Values

Posted by Barry Prendergast
Barry Prendergast
7,093 Points

This is driving me crazy. What am i missing?

<script>
      function arrayCounter (a){
        if (typeof a === 'undefined', 'string', 'number'){
                return 0;}
            return a.length;
      }
</script>
Barry Prendergast
Barry Prendergast
7,093 Points

I need to return the length of a, if a is an array.. Help

thomascawthorn
thomascawthorn
22,986 Points

without the 'if' statement, this function returns the length of the array..

I don't know why it's catching 'a' though.. maybe this might help

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof

Barry Prendergast
Barry Prendergast
7,093 Points

Thanks i got it finally, looking on the internet, the answer is:

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

1 Answer

Ryan Duchene
PLUS
Ryan Duchene
Courses Plus Student 46,022 Points
Ryan Duchene
Ryan Duchene
Courses Plus Student 46,022 Points

After checking out MDN (thanks, Thomas), I think this should work:

function arrayCounter( a ) {
    if ( Array.isArray( a ) ) {
        return a.length;
    }

    return 0;
}
Ryan Duchene
Ryan Duchene
Courses Plus Student 46,022 Points

My bad, didn't realize this had already been answered.