Example usage for java.util HashMap HashMap

Introduction

In this page you can find the example usage for java.util HashMap HashMap.

Prototype

public HashMap()

Source Link

Document

Constructs an empty HashMap with the default initial capacity (16) and the default load factor (0.75).

Usage

From source file:Main.java

public static void main(String[] argv) {

    Map<Number, String> numMap = new HashMap<Number, String>();

    numMap.put(.5, "half");
    numMap.put(1, "first");
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Map map = new HashMap();

    Object[] objectArray = map.keySet().toArray();
    MyClass[] array = (MyClass[]) map.keySet().toArray(new MyClass[map.keySet().size()]);

}

From source file:Main.java

public static void main(String[] argv) {

    Map<Integer, String> map = new HashMap<Integer, String>();

    map.put(1, "first");
    map.put(2, "second");
    // map.put(1, 2); <- Syntax error
}

From source file:Main.java

public static void main(String[] a) {

    Map<String, String> map = new HashMap<String, String>();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");
    map.remove("key3");

    System.out.println(map);/*from w ww .  jav a2 s.  c o m*/
}

From source file:Main.java

public static void main(String[] args) {
    HashMap<String, Integer> map = new HashMap<String, Integer>();

    map.put("a", 1);
    map.put("b", 2);

    System.out.println("Before removal");
    for (String s : map.keySet()) {
        System.out.println(s);/* w w  w.j av a  2 s  .  com*/
    }

    System.out.println("\n\nAfter removal");

    map.remove("a");
    for (String s : map.keySet()) {
        System.out.println(s);
    }
}

From source file:Main.java

public static void main(String[] a) {
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");
    map.clear();/*from  ww  w.  j  a v a 2 s  . co m*/

    System.out.println(map);
}

From source file:Main.java

public static void main(String[] a) {
    Map<String, String> map = new HashMap<String, String>();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");
    Map<String, String> map2 = new HashMap<String, String>();
    map2.put("key2", "value2");
    map2.put("key1", "value1");
    map2.put("key3", "value3");
    System.out.println(map1.equals(map2));
}

From source file:Main.java

public static void main(String[] a) {
    Map<String, String> map = new HashMap<String, String>();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");
    Map<String, String> map2 = new HashMap<String, String>();
    map2.put("key2", "value2");
    map2.put("key1", "value1");
    map2.put("key3", "value3");
    System.out.println(map2.equals(map2));
}

From source file:Main.java

public static void main(String[] a) {
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");

    System.out.println(map.containsKey("key1"));
    System.out.println(map.containsValue("value2"));
}

From source file:Main.java

public static void main(String[] args) {
    Map<String, Integer> map = new HashMap<String, Integer>();

    map.put("Age", 25);

    int age = map.get("Age");

    Integer newAge = age + 10;/*w  ww.  j a v a  2 s  . c o m*/
}