Big Endian vs Little Endian

Data stores in memory split in Bytes

Endianness:Order of bytes (of data) in memory

Big Endian stores Most significant byte First
Little Endian stores Least significant Byte First

Network: Big Endian
PCM: Little Endian
X86: Little Endian
Src:http://www.raywenderlich.com/12910/how-to-make-a-simple-playing-card-game-with-multiplayer-and-bluetooth-part-3/big-endian-vs-little-endian

PHP uninitialized variable evaluation


php > $user;
php > print var_dump(!$user);
PHP Notice: Undefined variable: user in php shell code on line 1
bool(true)
php > print var_dump($user);
PHP Notice: Undefined variable: user in php shell code on line 1
NULL
php > print var_dump(empty($user));
bool(true)




uninialized variable evaluates to NULL (with notice)

!$var evaluates to True

empty($var) evaluates to True