PHP Developer’s Dictionary IT-SC book 125 The 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 element at that location. If there are no previous elements, the function returns PHP Developer’s Dictionary IT-SC book 126 false. 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() PHP Developer’s Dictionary IT-SC book 127 Syntax 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 PHP Developer’s Dictionary IT-SC book 128 void 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) PHP Developer’s Dictionary IT-SC book 129 Description 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 int mhash_count(void ) . lowest). shuffle() PHP Developer’s Dictionary IT-SC book 127 Syntax void shuffle(array array) Description The shuffle() function, which was added in PHP 3.0.8 and PHP 4.0b4, randomizes. uasort() Syntax PHP Developer’s Dictionary IT-SC book 128 void uasort(array array, function cmp_function) Description The uasort() function, which was added in PHP 3.0.4 and PHP 4.0, sorts. 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.