– Hash Object Tip Sheet
Hash Object – Methods
declare hash obj();
declare hash obj(dataset: 'dataset_name',
duplicate: 'replace' | 'error', hashexp: n,
ordered: 'a' | 'd' | 'no', suminc: 'count_var');
Creates a hash object with the properties:
dataset: loads the hash object from a data set.
duplicate: controls how duplicate keys are handled
when loading from a data set.*
hashexp: n declares 2n slots for the hash object.
ordered: specifies a key sort order when using a hash
iterator or the output method.
suminc: count_var contains the increment value for a
key summary that is retrieved by the sum method.*
rc = obj.defineKey('key_var1', …, 'key_varN');
rc = obj.defineKey(all: 'yes');
Defines a set of hash object keys given by
key_var1…key_varN.
rc = obj.defineData('data_var1', …, 'data_varN');
rc = obj.defineData(all: 'yes');
Defines data, given by data_var1…data_varN, to be
stored in the hash object.
rc = obj.defineDone();
Indicates that key and data definitions are complete.
rc = obj.add();
rc = obj.add(key: key_val1, …, key: key_valN,
data: data_val1, …, data: data_valN);
Adds the specified data associated with the given key
to the hash object.
rc = obj.find();
rc = obj.find(key: key_val1, …, key: key_valN);
Determines whether the given key has been stored in
the hash object. If it has, the data variables are
updated and the return code is set to zero. If the key is
not found, the return code is non-zero.
All methods return zero for success
Hash Object – Methods
rc = obj.replace();
rc = obj.replace(key: key_val1,…, key: key_valN,
data: data_val1, …, data: data_valN);
Replaces the data associated with the given key with
new data as specified in data_val1…data_valN.
rc = obj.check();
rc = obj.check(key: key_val1, …, key: key_valN);
Checks whether the given key has been stored in the
hash object. The data variables are not updated.
Return codes are the same as for find.
rc = obj.remove();
rc = obj.remove(key: key_val1, …, key: key_valN);
Removes the data associated with the given key.
rc = obj.clear();
Removes all entries from a hash object without
deleting the hash object.*
rc = obj.output(dataset: 'dataset_name');
Creates dataset dataset_name which will contain the
data in the hash object.
rc = obj.sum(sum: sum_var);
rc = obj.sum(key: key_val1, …, key: key_valN,
sum: sum_var);
Gets the key summary for the given key and stores it in
the DATA Step variable sum_var. Key summaries are
incremented when a key is accessed.*
rc = obj.ref();
rc = obj.ref(key: key_val1, …, key: key_valN);
Performs a find operation for the current key. If the
key is not in the hash object, it will be added.*
rc = obj.equals(hash: 'hash_obj', result: res_var);
Determines if two hash objects are equal. If they are
equal, res_var is set to 1, otherwise it is set to zero.*
*Feature available in SAS 9.2 and later.
Hash Object – Attributes
i = obj.num_items;
Retrieves the number of elements in the hash object.
sz = obj.item_size;
Obtains the item size, in bytes, for an item in the hash
object.*
rc = obj.delete();
Deletes the hash object.
Hash Iterator – Methods
declare hiter iterobj('hash_obj');
Creates a hash iterator to retrieve items from the hash
object named hash_obj.
rc = iterobj.first();
Copies the data for the first item in the hash object into
the data variables for the hash object.
rc = iterobj.last();
Copies the data for the last item in the hash object into
the data variables for the hash object.
rc = iterobj.next();
Copies the data for the next item in the hash object into
the data variables for the hash object. A non-zero
value is returned if the next item cannot be retrieved.
Use iteratively to traverse the hash object and return
the data items in key order. If first has not been
called, next begins with the first item.
rc = iterobj.prev();
Copies the data for the previous item in the hash object
into the data variables for the hash object. A non-zero
value is returned if the next item cannot be retrieved.
Use iteratively to traverse the hash object and return
the data items in reverse key order. If last has not
been called, prev begins with the last item.
