undefined error while using array.length

Question

I am working on implementing a bubble sort method in JavaScript, here is my current Code:

 // Sort array (ascending)
function sort(array) {

  var sortedArray = array;
  // This swapped 'flag' tells the function whether or not it will
  // need to iterate over the array again to continue sorting  
  var swapped = false;

  for( var i = 1; i < array.length; i++ ) {
    var prev = array[i - 1];
    var current = array[i];

    // If the previous number is > than the current, swap them around
    if( prev > current ) {
      swapped = true;

      sortedArray[i] = prev;
      sortedArray[i - 1] = current;
    }

  }
  // If there has been a swap, sort over the array again
  if( swapped ) {
    return sort();
  }

    return sortedArray; 
}


var testArray = [1, 4, 27, 3, 2];


// Run the sort function
sort(testArray); // [1, 2, 3, 4, 27]

When I run this, I keep getting ' cannot read property .length of undefined'

But, I can console.log(array.length) right before the for loop and it returns a value.

Here is a repl.it of my code.

Why am I getting an 'undefined'?

Thanks Andy, that's it! I think I need my Monday morning coffee before attempting anything else. Thanks again! — HelloWorld
– HelloWorld, Commented Mar 31, 2014 at 14:13

Andy · Accepted Answer · 2014-03-31 14:15:47Z

2

As per my comment: you need to pass in array to the sort function again:

if (swapped) {
  return sort(array);
}

answered Mar 31, 2014 at 14:15

Andy

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Comments

mpm · Accepted Answer · 2014-03-31 14:14:46Z

0

 // If there has been a swap, sort over the array again
  if( swapped ) {
    return sort();
  }

You are returning sort() with no argument here.

answered Mar 31, 2014 at 14:14

mpm

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