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JavaScript JavaScript Foundations Functions Return Values

michel rodrigues
michel rodrigues
11,727 Points
Posted by michel rodrigues
michel rodrigues
11,727 Points

how can I verify in a function if some parameter is a number or string? Im quiet confused.

this is my code challenge, god I don't understand or maybe im loosing something.

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.

index.html 
<!DOCTYPE html>
<html lang="en">
  <head>
    <title>JavaScript Foundations: Functions</title>
    <style>
      html {
        background: #FAFAFA;
        font-family: sans-serif;
      }
    </style>
  </head>
  <body>
    <h1>JavaScript Foundations</h1>
    <h2>Functions: Return Values</h2>
    <script>

      function arrayCounter(array) {

        if (typeof array === 'undefined'){
            return 0;
            }
        return array.length;

      }

    </script>
  </body>
</html>

1 Answer

mikes02
mikes02
Courses Plus Student 16,968 Points 
function arrayCounter(array) {
    if (typeof array === 'undefined' || typeof array === 'number' || typeof array === 'string')
    {
        return 0;
    } else {
        return array.length;    
    }
}

Then to test you could do something like:

var cars = ['toyota','honda','mercedes'];
alert(arrayCounter(cars));