HashMap

C++

Java

Python3

include

#include <unordered_map>

import java.util.*;

new

std::unordered_map<int, int> t;

Hashtable<Integer, Integer> t = new Hashtable<>();

d = {}

add

t.insert(std::make_pair<int, int>(key, val));

t.put(key, val);

d[key] = val

get

int val = t.at(key);

Integer val = t.get(key);

val = d[key]

delete

t.erase(key);

t.remove(key);

del d[key]

iterate

for (Map.Entry<Integer, Integer> set : t.entrySet()) {
key=set.getKey();
val=set.getValue();
}

iterate

t.forEach((key, val)->{...})

for key in d:

check in table

std::unordered_map<int, int>::const_iterator it = t.find(key);
if (it != t.end())

if (t.containsKey(key))

if key in d.keys():

size

s.size()

s.size()

len(s)

check empty

if (s.empty())

if (s.isEmpty())

if not s: