Arrays

Arrays are stored using Zend's internal hash tables, which can be accessed using the zend_hash_*() API. For every array that you want to create, you need a new hash table handle, which will be stored in the ht member of the zval.value container.

There's a whole API solely for the creation of arrays, which is extremely handy. To start a new array, you call array_init().

zval *new_array;

MAKE_STD_ZVAL(new_array);

if(array_init(new_array) != SUCCESS)
{
    // do error handling here
}

If array_init() fails to create a new array, it returns FAILURE.

To add new elements to the array, you can use numerous functions, depending on what you want to do. Tabelle 33-1, Tabelle 33-2 and Tabelle 33-3 describe these functions. All functions return FAILURE on failure and SUCCESS on success.

Tabelle 33-1. Zend's API for Associative Arrays
Function	Description
add_assoc_long(zval *array, char *key, long n);() 	Adds an element of type long.
add_assoc_unset(zval *array, char *key);()	Adds an unset element.
add_assoc_bool(zval *array, char *key, int b);() 	Adds a Boolean element.
add_assoc_resource(zval *array, char *key, int r);() 	Adds a resource to the array.
add_assoc_double(zval *array, char *key, double d);() 	Adds a floating-point value.
add_assoc_string(zval *array, char *key, char *str, int duplicate);() 	Adds a string to the array. The flag duplicate specifies whether the string contents have to be copied to Zend internal memory.
add_assoc_stringl(zval *array, char *key, char *str, uint length, int duplicate); () 	Adds a string with the desired length length to the array. Otherwise, behaves like add_assoc_string().

Tabelle 33-2. Zend's API for Indexed Arrays, Part 1
Function	Description
add_index_long(zval *array, uint idx, long n);()	Adds an element of type long.
add_index_unset(zval *array, uint idx);()	Adds an unset element.
add_index_bool(zval *array, uint idx, int b);()	Adds a Boolean element.
add_index_resource(zval *array, uint idx, int r);()	Adds a resource to the array.
add_index_double(zval *array, uint idx, double d);()	Adds a floating-point value.
add_index_string(zval *array, uint idx, char *str, int duplicate);()	Adds a string to the array. The flag duplicate specifies whether the string contents have to be copied to Zend internal memory.
add_index_stringl(zval *array, uint idx, char *str, uint length, int duplicate);()	Adds a string with the desired length length to the array. This function is faster and binary-safe. Otherwise, behaves like add_index_string()().

Tabelle 33-3. Zend's API for Indexed Arrays, Part 2
Function	Description
add_next_index_long(zval *array, long n);()	Adds an element of type long.
add_next_index_unset(zval *array);()	Adds an unset element.
add_next_index_bool(zval *array, int b);()	Adds a Boolean element.
add_next_index_resource(zval *array, int r);()	Adds a resource to the array.
add_next_index_double(zval *array, double d);()	Adds a floating-point value.
add_next_index_string(zval *array, char *str, int duplicate);()	Adds a string to the array. The flag duplicate specifies whether the string contents have to be copied to Zend internal memory.
add_next_index_stringl(zval *array, char *str, uint length, int duplicate);()	Adds a string with the desired length length to the array. This function is faster and binary-safe. Otherwise, behaves like add_index_string()().

All these functions provide a handy abstraction to Zend's internal hash API. Of course, you can also use the hash functions directly - for example, if you already have a zval container allocated that you want to insert into an array. This is done using zend_hash_update()() for associative arrays (see Beispiel 33-3) and zend_hash_index_update() for indexed arrays (see Beispiel 33-4):

Beispiel 33-3. Adding an element to an associative array.

zval *new_array, *new_element;
char *key = "element_key";
      
MAKE_STD_ZVAL(new_array);
MAKE_STD_ZVAL(new_element);

if(array_init(new_array) == FAILURE)
{
    // do error handling here
}

ZVAL_LONG(new_element, 10);

if(zend_hash_update(new_array->value.ht, key, strlen(key) + 1, (void *)&new_element, sizeof(zval *), NULL) == FAILURE)
{
    // do error handling here
}

Beispiel 33-4. Adding an element to an indexed array.

zval *new_array, *new_element;
int key = 2;

MAKE_STD_ZVAL(new_array);
MAKE_STD_ZVAL(new_element);

if(array_init(new_array) == FAILURE)
{
    // do error handling here
}

ZVAL_LONG(new_element, 10);

if(zend_hash_index_update(new_array->value.ht, key, (void *)&new_element, sizeof(zval *), NULL) == FAILURE)
{
    // do error handling here
}

To emulate the functionality of add_next_index_*(), you can use this:

zend_hash_next_index_insert(ht, zval **new_element, sizeof(zval *), NULL)