Your code is wrong.

Really.

Haha hallelujah!

I was referring to kreitzo code, not yours, which seems fine this time ;)

Always nice to hear from you mate :D

Your code is still, if you allow me, quite ugly, not easily maintanable (using an associative array or a switch instead of a pointless list of ifs?) and fails to consider cases like t===80.

From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce:

Note: If initialValue isn't provided, reduce will execute the callback function starting at index 1, skipping the first index. If initialValue is provided, it will start at index 0.

If the array is empty and no initialValue was provided, TypeError would be thrown. If the array has only one element (regardless of position) and no initialValue was provided, or if initialValue is provided but the array is empty, the solo value would be returned without calling callback.

The initial value is like a backup value for when it's empty/only one item or there's a NaN value at index 0. Since reduce works by looking at index 0, if there's nothing there it returns an error.

1. First, your 'or' operator in the ternary conditional allows null values to pass through since array !== [] is true. This means it will try to sort the null value; leading to an error.
2. Your reduce function needs a starting value (what you want it to initially be, which will be 0). Simply add a comma and a zero after the addition operator -> .reduce((a,b)=>a+b, 0)

you cannot do that.

That's a good idea, however, look at this case: { '0': 'aBC deF Ghi', '1': undefined }. The second argument is "undefined" which means that the length of arguments is != 1 and therefore split() is performed on the undefined value. You should get into default arguments/parameters because they are really simple to make.

Sorry, this is a bug with the tests. They use titleCase(foo, undefined) instead of titleCase(foo) and so agruments.length is always 2. See

The JavaScript/CoffeeScript tests will pass undefined when this argument is unused.

(which might need more emphasis?)

Unfortunately I can't change the tests now as too many people have passed the kata.

The error is when there is not a second argument in the function. Your code tries to split minorWords, however this may not be included as an argument and therefore you need a default argument. You should also put the empty string/null/undefined check at the start so that it will return early and will not follow any other code.

Here is one:

function isEven(n) {
  return (n % 2 === 0);
}

Fixed, as per above comment. Thanks.

if(array == null)

That checks for null. ;-)

What were the errors? Suggests there aren't enough random tests if sometimes you can pass when you shouldn't