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JavaScript JavaScript Foundations Functions Return Values

Posted by max1234
max1234
1,497 Points

Function output 0 instead of array length

Why does this function return 0 for an array instead of the length of the array?

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

3 Answers

Kristen Law
Kristen Law
16,244 Points

You want to compare typeof a to 'undefined' or 'string' or 'number', so you would need to use the or operator: ||

See below:

function arrayCounter (a) {
    if (typeof a === 'undefined' || typeof a === 'string' || typeof a === 'number'){
        return 0;
    }
    return a.length;
}
Matthew Ludwigs
Matthew Ludwigs
11,197 Points
Matthew Ludwigs
Matthew Ludwigs
11,197 Points

Hey Max,

Hopefully I can help. First, I think while that if statement seems to work it, I do not think it really does. Maybe using the or operator to check your typeof on a would work. JS does not allow for the typeof a === "string", "undefined" syntax. For example:

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

I hope this helps!

Matt

max1234
max1234
1,497 Points
max1234
max1234
1,497 Points

Thank you - the "||" provided the solution for the problem!