Octal or not octal, that's the question

We know hexadecimal representations of numbers in code: 0x00 for example. A less well known number representation are octal numbers. Octal numbers are in C like languages defined by prefixing a number with a 0. This can result in weird bugs, especially when not knowing this format. Not-so-surprisingly PHP adds its special confusing powers to this feature.

     0815===0 = true
      010===8 = true
    "010"==10 = true
     "010"==8 = false
   "010"=="8" = false
  "010"=="10" = true
  "0xf"=="15" = true
    "08"=="0" = false
       018==1 = true
      "01"==0 = false
 "0xf"=="015" = true

Tested with:

<?
function test ($exp) {
 echo sprintf("%15s = %s\n",$exp,eval("return ".$exp.";")?"true":"false");
}

test("0815===0");
test("010===8"); // true
test('"010"==10'); // true
test('"010"==8'); // false
test('"010"=="8"'); // false
test('"010"=="10"'); // true
test('"0xf"=="15"');
test('"08"=="0"');
test('018==1');
test('"01"==0');
test('"0xf"=="015"');

Just another type coercion thingie.

Check this out:

<?
var_dump(1 == "1 dog"); // true
var_dump(1 == "1 cat"); // true
var_dump("1 cat" == "1 dog"); // false

var_dump(1 == "0x1 dog"); // true
var_dump("1 dog" == "0x1 dog"); // false

Result:

bool(true)
bool(true)
bool(false)
bool(true)
bool(false)

Transitivity is none of the things that the "==" operator respects at all. Using the "===" comparator works (in this case). Yet I find this thing funny.

This thing refers to their project as "The key innovation in the 3.0 release is the introduction of the PHP-like Lua".

I would like to point out that this comparison is an awful insult to anyone who uses Lua. I can only assume that the author are not aware of what PHP is at all. Or Lua. Or both.