ConcurrentNavigableMap method toString() in Java

A ConcurrentNavigableMap method toString() converts a string representation of this map. The string representation consists of a list of key-value mappings in the order returned by the map's entrySet view's iterator, enclosed in braces ("{}"). It returns a string representation of this map.

Syntax

 1 public String toString()

return : It returns a string representation of this map.

ConcurrentNavigableMap method toString()

 1 package com.java;
 2 
 3 import java.util.concurrent.ConcurrentSkipListMap;
 4 
 5 public class Main {
 6 
 7     public static void main(String[] args)  {
 8 
 9         ConcurrentSkipListMap<Integer, Integer> navigableMap = new ConcurrentSkipListMap<>();
 10         navigableMap.put(22, 222);
 11         navigableMap.put(11, 111);
 12         System.out.println("Map elements : " + navigableMap);
 13 
 14         // convert string representation
 15         String str = navigableMap.toString();
 16         System.out.println("A string representation : " + str);
 17     }
 18 }

In the above example, a ConcurrentSkipListMap object with key and value of type Integer and mappings added using put() method. A toString() method called that returns a string representation of this map which enclosed with curly braces. A resulting string assigned to the variable and print.

Output

 1 Map elements : {11=111, 22=222}
 2 A string representation : {11=111, 22=222}

ConcurrentNavigableMap method toString() with String

 1 package com.java;
 2 
 3 import java.util.concurrent.ConcurrentSkipListMap;
 4 
 5 public class StringExp {
 6 
 7     public static void main(String[] args) {
 8 
 9         ConcurrentSkipListMap<String, String> navigableMap = new ConcurrentSkipListMap<>();
 10 
 11         navigableMap.put("A1", "Welcome");
 12         navigableMap.put("A2", "IOGyan");
 13         navigableMap.put("A3", "Java");
 14         System.out.println("Map elements : " + navigableMap);
 15 
 16         // convert string representation
 17         String str = navigableMap.toString();
 18         System.out.println("A string representation : " + str);
 19     }
 20 }

In the above example, a ConcurrentSkipListMap object with key and value of type String and mappings added using put() method. A toString() method called that returns a string representation of this map which enclosed with curly braces. A resulting string assigned to the variable and print.

Output

 1 Map elements : {A1=Welcome, A2=IOGyan, A3=Java}
 2 A string representation : {A1=Welcome, A2=IOGyan, A3=Java}

ConcurrentNavigableMap method toString() with custom object

 1 package com.java;
 2 
 3 import java.util.concurrent.ConcurrentSkipListMap;
 4 
 5 public class Example {
 6 
 7     public static void main(String[] args) {
 8 
 9         Product pd1 = new Product(11, "Phone", 10, 23000.00);
 10         Product pd2 = new Product(22, "LCD", 2, 90000.32);
 11         Product pd3 = new Product(33, "TV", 5, 500000.94);
 12 
 13         ConcurrentSkipListMap<Product, String> navigableMap = new ConcurrentSkipListMap<>();
 14         navigableMap.put(pd1, "Welcome");
 15         navigableMap.put(pd2, "IOGyan");
 16         System.out.println("Map elements : " + navigableMap);
 17 
 18         // convert string representation
 19         String str = navigableMap.toString();
 20         System.out.println("A string representation : " + str);
 21     }
 22 }

In the above example, a ConcurrentSkipListMap object with key and value of type Product and String, a mappings added using put() method. A toString() method called that returns a string representation of this map which enclosed with curly braces. A resulting string assigned to the variable and print. It internally use toString() method of Product class to print Product object.

Output

 1 Map elements : {Phone 10 23000.0=Welcome, LCD 2 90000.32=IOGyan}
 2 A string representation : {Phone 10 23000.0=Welcome, LCD 2 90000.32=IOGyan}

Product class

 1 package com.java;
 2 
 3 public class Product implements Comparable<Product> {
 4     private final int pid;
 5     private final String name;
 6     private final long quantity;
 7 
 8     private final double price;
 9 
 10     public Product(int pid, String name, long quantity, double price) {
 11         this.pid = pid;
 12         this.name = name;
 13         this.quantity = quantity;
 14         this.price = price;
 15     }
 16 
 17     public int getPid() {
 18         return pid;
 19     }
 20 
 21     public String getName() {
 22         return name;
 23     }
 24 
 25     public long getQuantity() {
 26         return quantity;
 27     }
 28 
 29     public double getPrice() {
 30         return price;
 31     }
 32 
 33     @Override
 34     public String toString() {
 35         return this.name + " " + this.quantity + " " + this.price;
 36     }
 37 
 38     @Override
 39     public int compareTo(Product o) {
 40         return this.pid - o.pid;
 41     }
 42 }