Collections

Map_Sort_By_Value.java

// Sory by Value
public static LinkedHashMap<String, Integer> sortByValue(Map<String, Integer> map) {
    return map.entrySet()
        .stream()
        .sorted((Map.Entry.<String, Integer>comparingByValue().reversed()))
        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, (e1, e2) -> e1, LinkedHashMap::new));
}

// Count words in sentence
for (String word : arr) {
    map.put(word, map.getOrDefault(word, 0) + 1);
}

MapIteration.java

map.forEach((k, v) -> System.out.println(k + "=" + v));

for (Map.Entry<?, ?> entry : m.entrySet()) {     
	System.out.println(entry.getKey() + " = " + entry.getValue()); 
}

Iterator it = m.entrySet().iterator();
while (it.hasNext()) {
    Map.Entry pairs = (Map.Entry)it.next();
    System.out.println(pairs.getKey() + " = " + pairs.getValue());
}

String_Char_Count_Map.java

Map<String, Long> map = Arrays.stream(str.split("")).collect(Collectors.groupingBy(c -> c, Collectors.counting()));