digitalmars.D - Empty array vs. null array (WAS: Re: Arrays)
- Bruno Medeiros (6/9) Apr 26 2008 reverse is not true.
- Janice Caron (3/10) Apr 26 2008 If (array.length == 0) then it's an empty array.
- Bruno Medeiros (10/22) Apr 26 2008 True.
Walter Bright wrote:reverse is not true.2) An empty array is equal to a null pointer. Yikes!Not exactly, although a null array is also an empty array, theReally? So what exactly is the difference? -- Bruno Medeiros - Software Developer, MSc. in CS/E graduate http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D
Apr 26 2008
On 26/04/2008, Bruno Medeiros <brunodomedeiros+spam com.gmail> wrote:Walter Bright wrote: >> >> 2) An empty array is equal to a null pointer. Yikes! > > Not exactly, although a null array is also an empty array, the reverse is not true. Really? So what exactly is the difference?If (array.length == 0) then it's an empty array. If (array.ptr == 0 && array.length == 0) then it's a null array.
Apr 26 2008
Janice Caron wrote:On 26/04/2008, Bruno Medeiros <brunodomedeiros+spam com.gmail> wrote:True. But that only makes an empty array not the *same* as a null array. They are still equal (in terms of equality, think of the equality operator), which I believe is what the original poster was thinking about, and I agree. Since Walter refuted that by saying "Not exactly", I was trying to learn why, but probably Walter just misunderstood the OP. -- Bruno Medeiros - Software Developer, MSc. in CS/E graduate http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#DWalter Bright wrote: >> >> 2) An empty array is equal to a null pointer. Yikes! > > Not exactly, although a null array is also an empty array, the reverse is not true. Really? So what exactly is the difference?If (array.length == 0) then it's an empty array. If (array.ptr == 0 && array.length == 0) then it's a null array.
Apr 26 2008