java for map
Map<String, String> map = new HashMap<>();
for(Entry<String, String> entry:map.entrySet()) {
System.out.println("key: "+entry.getKey()+" value: "+entry.getValue());
}java for map
Map<String, String> map = new HashMap<>();
for(Entry<String, String> entry:map.entrySet()) {
System.out.println("key: "+entry.getKey()+" value: "+entry.getValue());
}map in java
MAP : is a (key-value format)
and keys are always unique,
and value can be duplicated.
- HashTable don't have null key, sychronized(thread-safe)
- LinkedHashMap can have null key, keeps order
- HasHMap can have null key, order is not guaranteed
- TreeMap doesn't have null key and keys are sortedmap java
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class Main {
public static void main(String[] args) {
//La fameuse syntaxe en diamant de Java 7
Map<Integer, String> hm = new HashMap<>();
hm.put(10, "1");
hm.put(20, "2");
hm.put(30, "3");
hm.put(40, "4");
hm.put(50, "5");
//Ceci va écraser la valeur 5
hm.put(50, "6");
System.out.println("Parcours de l'objet HashMap : ");
Set<Entry<Integer, String>> setHm = hm.entrySet();
Iterator<Entry<Integer, String>> it = setHm.iterator();
while(it.hasNext()){
Entry<Integer, String> e = it.next();
System.out.println(e.getKey() + " : " + e.getValue());
}
System.out.println("Valeur pour la clé 8 : " + hm.get(8));
Map<Integer, String> lhm = new LinkedHashMap<>();
lhm.put(10, "1");
lhm.put(20, "2");
lhm.put(30, "3");
lhm.put(40, "4");
lhm.put(50, "5");
System.out.println("Parcours de l'objet LinkedHashMap : ");
Set<Entry<Integer, String>> setLhm = lhm.entrySet();
Iterator<Entry<Integer, String>> it2 = setLhm.iterator();
while(it2.hasNext()){
Entry<Integer, String> e = it2.next();
System.out.println(e.getKey() + " : " + e.getValue());
}
}
}java map declaration
Map< String,Integer> hm =
new HashMap< String,Integer>();
hm.put("a", new Integer(100));
hm.put("b", new Integer(200));
hm.put("c", new Integer(300));
hm.put("d", new Integer(400));Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
