Java Programming Collections

Here you can copy some Java Programming collections for beginner. This code is simple and easy to understand.

1. How to convert array to collection:

import java.util.*;

import java.io.*;

public class ArrayToCollection{

   public static void main(String args[]) 

   throws IOException{

      BufferedReader in = new BufferedReader

      (new InputStreamReader(System.in));

      System.out.println("How many elements 

      you want to add to the array: ");

      int n = Integer.parseInt(in.readLine());

      String[] name = new String[n];

      for(int i = 0; i < n; i++){

         name[i] = in.readLine();

      }

      List list = Arrays.asList(name); 

      System.out.println();

      for(String li: list){

         String str = li;

         System.out.print(str + " ");

      }

   }

}

Result:

How many elements you want to add to the array:

red white green

red white green

2. How to overloads methods?

class MyClass {

   int height;

   MyClass() {

      System.out.println("bricks");

      height = 0;

   }

   MyClass(int i) {

      System.out.println("Building new House that is "

      + i + " feet tall");

      height = i;

   }

   void info() {

      System.out.println("House is " + height

      + " feet tall");

   }

   void info(String s) {

      System.out.println(s + ": House is "

      + height + " feet tall");

   }

}

public class MainClass {

   public static void main(String[] args) {

      MyClass t = new MyClass(0);

      t.info();

      t.info("overloaded method");

      //Overloaded constructor:

      new MyClass();

   }

}

Result:

Building new House that is 0 feet tall.

House is 0 feet tall.

Overloaded method: House  is 0 feet tall.

bricks