next Syntax mixed nextarray array Description The next function advances the internal pointer by one and returns the element located at this new location.. The current function retur
Trang 1The list() language construct is used to assign a list of variables in one operation The construct list() is commonly used to assign multiple return values of a function
to variables
next()
Syntax
mixed next(array array)
Description
The next() function advances the internal pointer by one and returns the element located at this new location If there are no more elements in array to advance to,
the function returns false Note that this function also returns false if the value of the element at this location is empty
pos()
Syntax
mixed pos(array array)
Description
The pos() function is an alias to the current() function The current() function returns the element in array that is currently being pointed to by the internal
pointer Every array has this internal pointer, which is initialized to point to the first element inserted into the array If the internal pointer points beyond the element list, the function returns false
prev()
Syntax
mixed prev(array array)
Description
The prev() function rewinds the internal array pointer by one and returns the
Trang 2false Note that this function also returns false if the value of the element at this location is empty
range()
Syntax
array range(int low, int high)
Description
The range() function, which was added in PHP 3.0.8 and PHP 4.0b4, returns an array of integers from low to high
$array1 = range(1,4);//returns (1,2,3,4)
reset()
Syntax
mixed reset(array array)
Description
The reset() function moves the internal array pointer to the first element in array
and returns the value of the first element
rsort()
Syntax
void rsort(array array)
Description
The rsort() function sorts the array in reverse order (highest to lowest)
shuffle()
Trang 3Syntax
void shuffle(array array)
Description
The shuffle() function, which was added in PHP 3.0.8 and PHP 4.0b4, randomizes the order of the elements in array
sizeof()
Syntax
int sizeof(array array)
Description
The sizeof() function returns the number of elements in the array Empty
elements are included in the count This function is similar to count(), but is used specifically for arrays
$array1 = array (1,2,3,4,5,"pos"=>"",);
echo sizeof ($array1);//displays 6
sort()
Syntax
void sort(array array)
Description
The sort( ) function orders the elements of array The resulting array is sorted
from lowest to highest
uasort()
Syntax
Trang 4void uasort(array array, function cmp_function)
Description
The uasort() function, which was added in PHP 3.0.4 and PHP 4.0, sorts the array based on a user-defined comparison function The array indices maintain their
relation to the array elements with which they are associated
uksort()
Syntax
void uksort(array array, function cmp_function)
Description
The uksort() function , which was added in PHP 3.0.4 and PHP 4.0, sorts the array
by keys using a user-defined comparison function
usort()
Syntax
void usort(array array, function cmp_function)
Description
The usort() function, which was added in PHP 3.0.3 and PHP 4.0, sorts the array
by values using a user-defined comparison function
Dynamic Loading
Loading additional libraries at runt ime can extend the functionality of PHP After the external libraries have been loaded, you can call functions from this library as though they were part of PHP
dl()
Syntax
int dl(string library)
Trang 5Description
The dl() function loads the library , which is a PHP extension The library should
be placed in the directory specified by the extension_dir directive
Hash()
PHP offers many hashing options through the use of the mhash library To utilize these functions, you must download the library from http://sasweb.de/mhash/ and then compile PHP with the with-mhash option to enable it The hashing routines include SHA1, GOST, HAVAL, MD5, RIPEMD160, TIGER, and CRC32 checksums
mhash_get_hash_name()
Syntax
string mhash_get_hash_name(int hash)
Description
The mhash_get_hash_name() function, which was added in PHP 3.0.9 and PH P 4.0, returns the name of the hash associated with hash , which represents a hash ID If
no hash name corresponds to the hash ID, the function returns false
mhash_get_block_size()
Syntax
int mhash_get_block_size(int hash)
Description
The mhash_get_block_size() function, which was added in PHP 3.0.9 and PHP 4.0, returns the block size for a given hash
mhash_count()
Syntax