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PHP extension check if key exist

I am actually to code an extension php (it's wirte in C). Any way to know if a key exists in assoc array ? I use add_assoc_string but this function erase data if key exist. Currently I do this :

array_init(return_value);

add_index_long(return_value, "key1", "value", 1);
add_index_long(return_value, "key2", "value6", 1);
add_index_long(return_value, "key1", "value2", 1);   //here I erase previous key1 by value2

Is it possible to check if key1 for example is exists ? Maybe Can I use hashTable but I find no example.

EDIT

I have finaly find solution, to check if key exist in zaval array I do

if( zend_hash_exists(Z_ARRVAL_P(return_value), "key", sizeof("key")) ){
    //key exist
}
Solution

  • You can use zend_hash_index_exists(Z_ARRVAL_P(return_value)) from here php-src.

    Functions family starting from array_ is just wrappers to simplify usage of zend hash table API. Look at the source code of array_init(). You'll see that under the hood it calls zend_hash_init(). So just use appropriate type casting in your code.

    More examples how to work with arrays/hast tables in phpinternalsbook. Also you always can find a lot of useful examples directly in PHP source code repo. For example for this particular case - here.

    PS: Also, it looks like this code is not working:

    ...
add_index_long(return_value, "key1", "value", 1);

    because the real signature is add_index_long(zval *arg, zend_ulong idx, zend_long n), so one cannot use "key1" as zend_ulong idx and "value" as zend_long n due to type mismatch.