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); array_init(new_array); |
To add new elements to the array, you can use numerous functions, depending on what you want to do. Table 33-1, Table 33-2 and Table 33-3 describe these functions. All functions return FAILURE on failure and SUCCESS on success.
Table 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(). |
add_assoc_zval(zval *array, char *key, zval *value);() | Adds a zval to the array. Useful for adding other arrays, objects, streams, etc... |
Table 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()(). |
add_index_zval(zval *array, uint idx, zval *value);() | Adds a zval to the array. Useful for adding other arrays, objects, streams, etc... |
Table 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()(). |
add_next_index_zval(zval *array, zval *value);() | Adds a zval to the array. Useful for adding other arrays, objects, streams, etc... |
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 Example 33-3) and zend_hash_index_update() for indexed arrays (see Example 33-4):
Example 33-4. Adding an element to an indexed array.
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To emulate the functionality of add_next_index_*(), you can use this:
zend_hash_next_index_insert(ht, zval **new_element, sizeof(zval *), NULL) |
Note: To return arrays from a function, use array_init() and all following actions on the predefined variable return_value (given as argument to your exported function; see the earlier discussion of the call interface). You do not have to use MAKE_STD_ZVAL on this.
Tip: To avoid having to write new_array->value.ht every time, you can use HASH_OF(new_array), which is also recommended for compatibility and style reasons.