Java HashMap remove()

Java HashMap [Java HashMap] Java HashMap

remove() hashMap key (key-value)

remove() 

hashmap.remove(Object key, Object value);

hashmap HashMap

  • key -
  • value- (key-value) key value

key key key null key HashMap null

key value true false

remove()

import java.util.HashMap;

class Main {
    public static void main(String[] args) {

        HashMap<Integer, String> sites = new HashMap<>();
        sites.put(1, "Google");
        sites.put(2, "Runoob");
        sites.put(3, "Taobao");
        System.out.println("HashMap: " + sites);

        // key2
        String siteName = sites.remove(2);  // return Runoob
        System.out.println(": " + siteName);
        System.out.println(" HashMap: " + sites);
    }
}

HashMap: {1=Google, 2=Runoob, 3=Taobao}
: Runoob
 HashMap: {1=Google, 3=Taobao}

sites HashMap remove() sites key value value

remove() key value

import java.util.HashMap;

class Main {
    public static void main(String[] args) {

        HashMap<Integer, String> sites = new HashMap<>();
        sites.put(1, "Google");
        sites.put(2, "Runoob");
        sites.put(3, "Taobao");
        System.out.println("HashMap: " + sites);

        // key2
        Boolean flag1 = sites.remove(1, "Google");  // return true
        Boolean flag2 = sites.remove(2, "Weibo");  // return false
        System.out.println(" flag1: " + flag1);
        System.out.println(" flag2: " + flag2);
        System.out.println(" HashMap: " + sites);
    }
}

 flag1: true
 flag2: false
 HashMap: {2=Runoob, 3=Taobao}

sites HashMap HashMap 3 

Boolean flag1 = sites.remove(1, "Google");  //  true
Boolean flag2 = sites.remove(2, "Weibo");   //  false

remove() key value HashMap key-value true false

Java HashMap [Java HashMap] Java HashMap