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JavaScript JavaScript Foundations Functions Return Values

Posted by Muhammad Ali Khan
Muhammad Ali Khan
8,227 Points

Checking if 'Undefined'

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.

var my_arrray = [ 1 , 2 , 3 ];
      function arrayCounter(my_array){
        if (my_array.isArray) {
            var a = my_array.length
          } 
        else {
        a = 0
          }
        return a
      }

Bummer! You're not checking if 'undefined' is being passed in

Please help

5 Answers

Carla Thomas
seal-mask
.a{fill-rule:evenodd;}techdegree
Carla Thomas
Front End Web Development Techdegree Student 16,039 Points
Carla Thomas
.a{fill-rule:evenodd;}techdegree
Carla Thomas
Front End Web Development Techdegree Student 16,039 Points

I found the "answer" here in the forum...it makes sense but I cannot get it to work in the challenge. Here's the link to the answer....please let me know if you can make that code work

https://teamtreehouse.com/forum/this-is-driving-me-crazy-what-am-i-missing

The answer

function arrayCounter(array) 
      { if (typeof array === "string" || typeof array === "number"|| typeof array === "undefined")
      { return 0; } 
      else { return array.length; } }
James Andrews
James Andrews
7,245 Points

Programmatically this code works. Why it doesn't work in the challenge I couldn't say as I haven't taken the javascript track yet

James Andrews
James Andrews
7,245 Points
James Andrews
James Andrews
7,245 Points 
if(typeof my_array === 'undefined'){
   // handle error
 }
else
{
// your code here etc...
}
James Andrews
James Andrews
7,245 Points
James Andrews
James Andrews
7,245 Points

...

Muhammad Ali Khan
Muhammad Ali Khan
8,227 Points
Muhammad Ali Khan
Muhammad Ali Khan
8,227 Points

Carla Thomas i got it right the first time as well but now when i try it, it keeps on giving me syntax error...strange

Adama Sy
Adama Sy
7,076 Points
Adama Sy
Adama Sy
7,076 Points

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

    else {return array.length};
     }