Example usage for java.util Map containsKey

Introduction

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

Prototype

boolean containsKey(Object key);

Source Link

Document

Returns true if this map contains a mapping for the specified key.

Usage

From source file:Counter.java

public static void main(String[] args) {
    Map hm = new HashMap();
    for (int i = 0; i < 10; i++) {
        Integer r = new Integer(20);
        if (hm.containsKey(r))
            ((Counter) hm.get(r)).i++;/*from  w ww  .j a  va 2 s  .  c  o  m*/
        else
            hm.put(r, new Counter());
    }
    System.out.println(hm);
}

From source file:Main.java

public static void main(String[] args) {
    String yourString = "UNDERSTAND";
    Map<Character, Integer> count = new TreeMap<Character, Integer>();
    for (char c : yourString.toCharArray()) {
        if (count.containsKey(c)) {
            count.put(c, (int) count.get(c) + 1);
        } else {//from  ww  w  . ja  va  2  s. c o m
            count.put(c, 1);
        }
    }
    System.out.println(count);
}

From source file:Main.java

public static void main(String args[]) {

    String s = "this is a test this is a test";
    String[] splitted = s.split(" ");
    Map<String, Integer> hm = new HashMap<String, Integer>();

    for (int i = 0; i < splitted.length; i++) {
        if (hm.containsKey(splitted[i])) {
            int cont = hm.get(splitted[i]);
            hm.put(splitted[i], cont + 1);
        } else {//w ww.  ja  v a2s.c  o  m
            hm.put(splitted[i], 1);
        }
    }
    System.out.println(hm);
}

From source file:MainClass.java

public static void main(String[] a) {

    Map map = new HashMap();
    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) {

    String sentence = "is this a sentence this is a test";
    String[] myStringArray = sentence.split("\\s"); // Split the sentence by
                                                    // space.

    Map<String, Integer> wordOccurrences = new HashMap<String, Integer>(myStringArray.length);

    for (String word : myStringArray) {
        if (wordOccurrences.containsKey(word)) {
            wordOccurrences.put(word, wordOccurrences.get(word) + 1);
        } else {/*ww w  .  j  a v a  2s . c o  m*/
            wordOccurrences.put(word, 1);
        }
    }
    for (String word : wordOccurrences.keySet()) {
        if (wordOccurrences.get(word) > 1) {
            System.out.println("1b. - Tokens that occurs more than once: " + word + "\n");
        }
    }
}

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");

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

From source file:Counter.java

public static void main(String[] args) {
    Map hm = new HashMap();
    for (int i = 0; i < 10000; i++) {
        // Produce a number between 0 and 20:
        Integer r = new Integer(rand.nextInt(20));
        if (hm.containsKey(r))
            ((Counter) hm.get(r)).i++;/*from  w  w  w. j  a v a  2s. c  o m*/
        else
            hm.put(r, new Counter());
    }
    System.out.println(hm);
}

From source file:Main.java

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

    String blah = "aaaabbbbddd";

    for (int i = 0; i < blah.length(); i++) {
        char c = blah.charAt(i);
        if (!map.containsKey(c)) {
            map.put(c, 1);/*from  ww w. ja v  a  2  s .  co m*/
        } else {
            map.put(c, (map.get(c) + 1));
        }
    }

    for (Map.Entry<Character, Integer> entry : map.entrySet()) {
        System.out.print(entry.getKey() + "" + entry.getValue());
    }
}

From source file:Weak.java

public static void main(String args[]) {
    final Map map = new WeakHashMap();
    map.put(new String("Java2s"), "www.java2s.com");
    Runnable runner = new Runnable() {
        public void run() {
            while (map.containsKey("Java2s")) {
                try {
                    Thread.sleep(500);
                } catch (InterruptedException ignored) {
                }//  ww  w .j  av a  2s  .c  o  m
                System.out.println("Waiting");
                System.gc();
            }
        }
    };
    Thread t = new Thread(runner);
    t.start();
    System.out.println("Main waiting");
    try {
        t.join();
    } catch (InterruptedException ignored) {
    }
}

From source file:Main.java

public static void main(String args[]) {
    final Map<String, String> map = new WeakHashMap<String, String>();
    map.put(new String("A"), "B");
    Runnable runner = new Runnable() {
        public void run() {
            while (map.containsKey("A")) {
                try {
                    Thread.sleep(500);
                } catch (InterruptedException ignored) {
                }/*  ww  w .  ja  v  a2  s.co m*/
                System.gc();
            }
        }
    };

    Thread t = new Thread(runner);
    t.start();
    try {
        t.join();
    } catch (InterruptedException ignored) {
    }
}