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Java Collection, HashSet Exercises: Iterate through all elements in a hash list

Java Collection, HashSet Exercises: Exercise-2 with Solution

Write a Java program to iterate through all elements in a hash list.

Sample Solution:

Java Code:

import java.util.*;
import java.util.Iterator;
  public class Exercise2 {
  public static void main(String[] args) {
         // Create a empty hash set
     HashSet<String> h_set = new HashSet<String>();
   // use add() method to add values in the hash set
          h_set.add("Red");
          h_set.add("Green");
          h_set.add("Black");
          h_set.add("White");
          h_set.add("Pink");
          h_set.add("Yellow");

  // set Iterator 
    Iterator<String> p = h_set.iterator();
  // Iterate the hash set
   while (p.hasNext()) {
   System.out.println(p.next());
   }
   }
}

Sample Output:

Red                                                                    
White                                                                  
Pink                                                                   
Yellow                                                                 
Black                                                                  
Green

Flowchart:

Flowchart: Iterate through all elements in a hash list.

Java Code Editor:

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Java: Tips of the Day

Try and catch:

Java is excellent at catching errors, but it can only recover gracefully if you tell it what to do. The cascading hierarchy of attempting to perform an action in Java starts with try, falls back to catch, and ends with finally. Should the try clause fail, then catch is invoked, and in the end, there's always finally to perform some sensible action regardless of the results. Here's an example:

try {
        cmd = parser.parse(opt, args); 
       
        if(cmd.hasOption("help")) {
                HelpFormatter helper = new HelpFormatter();
                helper.printHelp("Hello ", opt);
                System.exit(0);
                }
        else {
                if(cmd.hasOption("shell") || cmd.hasOption("s")) {
                String target = cmd.getOptionValue("tgt");
                } // else
        } // fi
} catch (ParseException err) {
        System.out.println(err);
        System.exit(1);
        } //catch
        finally {
                new Hello().helloWorld(opt);
        } //finally
} //try

It's a robust system that attempts to avoid irrecoverable errors or, at least, to provide you with the option to give useful feedback to the user. Use it often, and your users will thank you!

Ref: https://red.ht/3EZc9OC