getAtKeyLeq(keys: KeyType): MemberType;
The getAtKeyLeq method of the Dictionary class returns a reference to an object in the receiver collection with a key equal to or less than the value specified in the keys parameter. If the specified key is not found, the object in the dictionary before the specified key is returned. If no entry less than or equal to the key is found, this method returns a null value.
When dealing with a descending key dictionary, the terms greater than, less than, and so on, indicate the order of the dictionary keys. For example, C is less than B for a descending alpha key and 10 is less than 5 for a descending numeric key.