No, this way it is going over the array two times (once each per array_filter).

I think this way, as soon as it finds the outlier it will stop the foreach consuming less memory than loop the entire array.

Why is this line needed? @$text[$len+$i] = @$text[$i] = '';

Oh, it`s very interesting solution=)

Great solution. It shows a lot.

I got why it happens because used assertEquals instead of assertSame, 10 == true && ture == 10. https://stackoverflow.com/a/10254238/8574922

Way too convluted.