Loop through the items of a HashMap with a for-each loop.Note: Use the keySet() method if you only want the keys, and use the values() method if you only want the values:ExampleGet your own Java Server // Print keys for (String i : capitalCities.keySet()) { System.out.println(...
Loop Through a HashMap Loop through the items of aHashMapwith afor-eachloop. Note:Use thekeySet()method if you only want the keys, and use thevalues()method if you only want the values: Example // Print keysfor(Stringi:capitalCities.keySet()){System.out.println(i);} ...
capitalCities.clear(); HashMap Size capitalCities.size(); Loop Through a HashMap Use thekeySet()method if you only want the keys, anduse thevalues()method if you only want the values: //Print keysfor(String i : capitalCities.keySet()) { System.out.println(i); }//Outputs:USA Norway...
packagecom.programiz.hashmap;importjava.util.HashMap;publicclassCreateHashMap{publicstaticvoidmain(String[] args){// Creating a hashmap of even numbersHashMap<String, Integer> evenNumbers =newHashMap<>(); evenNumbers.put("Two",2); evenNumbers.put("Four",4); System.out.println("HashMap1:...
Here, the keySet() method returns a set view of all the keys present in the hashmap. The keySet() method can also be used with the for-each loop to iterate through each key of the hashmap. Example 2: keySet() Method in for-each Loop import java.util.HashMap; class Main { public...
1. private Map selectSqls = Collections.synchronizedMap(new HashMap()) 2. public Map executeSelect(final TableConfig tableConfig, Map keys) { 3. PreparedSql psql = null; 4. synchronized(selectSqls) { 5. if (selectSqls.get(tableConfig.getId()) == null) { 1. 2. 3. 4. 5. 13. ...
TreeMap 一种键值有序排列的映射表 EnumMap 一种键值属于枚举类型的映射表 LinkedHashMap 一种可以记住键 / 值项添加次序的映射表 WeakHashMap 一种其值无用武之地后可以被垃圾回收器回收的映射表 IdentityHashMap 一种用 == 而不是用 equals 比较键值的映射表 集合框架中的类: 在Java 程序设计语言中,所有...
(See below for * TreeNode subclass, and in LinkedHashMap for its Entry subclass.) */ static class Node<K,V> implements Map.Entry<K,V> { final int hash; final K key; V value; Node<K,V> next; Node(int hash, K key, V value, Node<K,V> next) { this.hash = hash; this.key...
7042126 core-libs (alt-rt) HashMap.clone implementation should be re-examined 8006593 core-libs Initialization bottleneck in Maps due to use of j.u.Random 7094176 core-libs (tz) Incorrect TimeZone display name when DST not applicable / disabled ...
more lines removed here to reduce output... 1118: 1 8 java.util.Hashtable$EmptyIterator 1119: 1 8 sun.java2d.pipe.SolidTextRenderer Total 61297 101520402.7.3 Heap Histogram of Core FileWhen the jmap -histo command is executed on a core file, the tool prints the size, count, and class...