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JavaScript JavaScript Foundations Functions Return Values

Posted by Micah Dunson
Micah Dunson
34,368 Points

how do I find the length of "X" array passed in an array or 0 if a string, number, or undefined is passed?

The question is create a function "arrayCounter" that takes a parameter which is an array. The function must find the length of the array passed in or 0 if a string. number, or undefined value is passed in.

I don't know how to call out an array item without a name to define its length

I also don't understand how you would expect to get the length if the array contains a 'string', 'number', or 'undefined' value passed in it and you call for a return of 0. They can all be contained in an array

2 Answers

Chris Hubbard
Chris Hubbard
2,253 Points

@micah dunson

Haven't done this specific lesson so I hope I am leading you the right way here. Also, there are a couple different ways you could tackle this (provided I am properly understanding your question). Take a look at the comments in the function below.

function arrayCounter (param) {
// Use Array.isArray() method to make sure function param is an array
// Using typeof() operator will return "object" on an array in Javascript
  var paramType = typeof(param);
  var isArray  = Array.isArray(param);
  if ( isArray ) {
    return param.length;
  } else if (paramType === "string" || paramType === "number" || paramType === "undefined") {
     return 0;
  }
}
Micah Dunson
Micah Dunson
34,368 Points

I have not covered this method of .isArray before. Thank you. This worked perfect and makes perfect sense.

Andrew Shook
Andrew Shook
31,709 Points
Andrew Shook
Andrew Shook
31,709 Points

This question comes up a lot on the forum. You can find the answer you are looking for here. Best of luck.

Micah Dunson
Micah Dunson
34,368 Points

Thanks a million. I knew I wasn't crazy about some things lol You've been a great help to my learning and sanity hahaha.