в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

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2010-05-31T14:11:42Z

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== Hashtable: clear() ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
table.clear();
System.out.println(table);
}
}

</source>



== Hashtable: clone() ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
Hashtable tableCopy = (Hashtable)table.clone();
System.out.println(tableCopy);
}
}

</source>



== Hashtable: containsKey(Object key) ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] args) {
Hashtable<String, String> ht = new Hashtable<String, String>();
ht.put("1", "One");
ht.put("2", "Two");
ht.put("3", "Three");
boolean blnExists = ht.containsKey("2");
System.out.println("2 exists in Hashtable ? : " + blnExists);
}
}

</source>



== Hashtable: contains(Object value) ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
System.out.println(table.contains("value3"));
}
}

</source>



== Hashtable: elements() ==



<source lang="java">

import java.util.Collection;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
public class Main {
public static void main(String[] args) {
Hashtable<String, String> ht = new Hashtable<String,String>();
ht.put("1", "One");
ht.put("2", "Two");
ht.put("3", "Three");
Collection c = ht.values();
Iterator itr = c.iterator();
while (itr.hasNext()){
System.out.println(itr.next());
}
c.remove("One");
Enumeration e = ht.elements();
while (e.hasMoreElements()){
System.out.println(e.nextElement());
}
}
}

</source>



== Hashtable: entrySet() ==



<source lang="java">

/*
{three=four, two=three, four=five, one=two}
4
three : four
two : three
four : five
one : two
three : four
two : three
four : five
one : two
*/
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
public class MainClass {
public static void main(String args[]) throws Exception {
Hashtable hash = new Hashtable(89);
hash.put("one", "two");
hash.put("two", "three");
hash.put("three", "four");
hash.put("four", "five");
System.out.println(hash);
System.out.println(hash.size());
Enumeration e = hash.keys();
while (e.hasMoreElements()) {
String key = (String) e.nextElement();
System.out.println(key + " : " + hash.get(key));
}
Set set = hash.entrySet();
Iterator it = set.iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
System.out.println(entry.getKey() + " : " + entry.getValue());
}
}
}

</source>



== Hashtable: get(E e) ==



<source lang="java">

/*
* Output:
Beijing is located in China
*/
import java.util.Hashtable;
public class MainClass {
public static void main(String args[]) {
Hashtable ht = new Hashtable();
ht.put("Tokyo", "Japan");
ht.put("Beijing", "China");
ht.put("Bangkok", "Thailand");
String city = "Beijing";
String country = (String) ht.get(city);
if (country != null)
System.out.println(city + " is located in " + country);
else
System.out.println(city + " is not located in the hashtable");
}
}

</source>



== Hashtable: isEmpty() ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
System.out.println(table.isEmpty());
System.out.println(table.size());
}
}

</source>



== Hashtable: iterator() ==



<source lang="java">

/**
*Output:
A: 4.34
E: -9.08
D: 9.22
C: 8.0
B: 3.22
A"s new balance: 1004.34
*/
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
public class MainClass {
public static void main(String args[]) {
Hashtable<String, Double> balance = new Hashtable<String, Double>();
String str;
double bal;
balance.put("A", 4.34);
balance.put("B", 3.22);
balance.put("C", 8.00);
balance.put("D", 9.22);
balance.put("E", -9.08);
Set<String> set = balance.keySet();
Iterator<String> itr = set.iterator();
while (itr.hasNext()) {
str = itr.next();
System.out.println(str + ": " + balance.get(str));
}
System.out.println();
bal = balance.get("A");
balance.put("A", bal + 1000);
System.out.println("A"s new balance: " + balance.get("A"));
}
}

</source>



== Hashtable: keys() ==



<source lang="java">

/*
* Output:
key = apple; value = red
key = strawberry; value = red
*/
import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
public static void main(String args[]) {
Hashtable hashtable = new Hashtable();
hashtable.put("apple", "red");
hashtable.put("strawberry", "red");
Enumeration e = hashtable.keys();
while(e.hasMoreElements()) {
Object k = e.nextElement();
Object v = hashtable.get(k);
System.out.println("key = " + k + "; value = " + v);
}
}
}

</source>



== Hashtable: keySet() ==



<source lang="java">

/**
*Output:
A: 4.34
E: -9.08
D: 9.22
C: 8.0
B: 3.22
A"s new balance: 1004.34
*/
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
public class MainClass {
public static void main(String args[]) {
Hashtable<String, Double> balance = new Hashtable<String, Double>();
String str;
double bal;
balance.put("A", 4.34);
balance.put("B", 3.22);
balance.put("C", 8.00);
balance.put("D", 9.22);
balance.put("E", -9.08);
Set<String> set = balance.keySet();
Iterator<String> itr = set.iterator();
while (itr.hasNext()) {
str = itr.next();
System.out.println(str + ": " + balance.get(str));
}
System.out.println();
bal = balance.get("A");
balance.put("A", bal + 1000);
System.out.println("A"s new balance: " + balance.get("A"));
}
}

</source>



== Hashtable: putAll(Map<K,V> t) ==



<source lang="java">

import java.util.Hashtable;
public class Main{
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
Hashtable<String,String> table2 = new Hashtable<String,String>();
table2.put("key4", "value4");
table2.put("key5", "value5");
table2.put("key6", "value6");
table2.putAll(table);
System.out.println(table2);
}
}

</source>



== Hashtable: put(K key, V value) ==



<source lang="java">

/*
* Output:
*
a: a
b: 2.0
c: b
d: 30

*
*
*/
import java.util.Dictionary;
import java.util.Hashtable;
public class MainClass {
public static void main(String args[]) {
Hashtable ht = new Hashtable();
ht.put("a", "a");
ht.put("b", new Double(2));
ht.put("c", "b");
ht.put("d", new Integer(30));
show(ht);
}
static void show(Dictionary d) {
System.out.println("a: " + d.get("a"));
System.out.println("b: " + d.get("b"));
System.out.println("c: " + d.get("c"));
System.out.println("d: " + d.get("d"));
}
}

</source>



== Hashtable: remove(Object key) ==



<source lang="java">

import java.util.Hashtable;
public class Main{
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
table.remove("key1");
System.out.println(table);
}
}

</source>



== Hashtable: size() ==



<source lang="java">

import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
System.out.println(table.isEmpty());
System.out.println(table.size());
}
}

</source>



== Hashtable: values() ==



<source lang="java">

import java.util.Enumeration;
import java.util.Hashtable;
public class Main {
public static void main(String[] s) {
Hashtable<String,String> table = new Hashtable<String,String>();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
Enumeration e = table.elements();
while (e.hasMoreElements()) {
String key = (String) e.nextElement();
System.out.println(key + " : " + table.get(key));
}
System.out.println(table.values());
}
}

</source>



== new Hashtable() ==



<source lang="java">

/*
* Output:
*
a: a
b: 2.0
c: b
d: 30

*
*
*/
import java.util.Dictionary;
import java.util.Hashtable;
public class MainClass {
public static void main(String args[]) {
Hashtable ht = new Hashtable();
ht.put("a", "a");
ht.put("b", new Double(2));
ht.put("c", "b");
ht.put("d", new Integer(30));
show(ht);
}
static void show(Dictionary d) {
System.out.println("a: " + d.get("a"));
System.out.println("b: " + d.get("b"));
System.out.println("c: " + d.get("c"));
System.out.println("d: " + d.get("d"));
}
}

</source>



== new Hashtable < K, V > () ==



<source lang="java">

/**
*Output:
A: 3434.34
*/
import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
public static void main(String args[]) {
Hashtable<String, Double> balance = new Hashtable<String, Double>();
Enumeration<String> names;
String str;
balance.put("A", 3434.34);
names = balance.keys();
while (names.hasMoreElements()) {
str = names.nextElement();
System.out.println(str + ": " + balance.get(str));
}
System.out.println();
}
}

</source>

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