std::collections::HashMap API Reference
Rust's HashMap<K, V> — a hash map with quadratic probing and SipHash by default.
HashMap<K, V>
A hash map implemented with quadratic probing and SipHash 1-3 (or 2-4) hashing.
HashMap::new() -> HashMap<K, V>Creates an empty HashMap with the default hasher and capacity.
Returns: HashMap<K, V>
map.insert(k: K, v: V) -> Option<V>Inserts a key-value pair. If the key already existed, the old value is returned.
Returns: Option<V>
map.get<Q: ?Sized>(&self, k: &Q) -> Option<&V>Returns a reference to the value corresponding to the key.
Returns: Option<&V>
map.remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V>Removes a key from the map, returning the value at the key if the key was previously in the map.
Returns: Option<V>
map.len() -> usizeReturns the number of elements in the map.
Returns: usize
map.contains_key<Q: ?Sized>(&self, k: &Q) -> boolReturns true if the map contains a value for the specified key.
Returns: bool
map.iter() -> Iter<K, V>Returns an iterator visiting all key-value pairs in arbitrary order.
Returns: Iter<K, V>