Collections Framework

 class demo
 {
  public static void main(String[] args) 
  {
    ArrayList arrayList=new ArrayList();
    arrayList.add(2);
    arrayList.add(4);
    arrayList.add(6);
    arrayList.add(10);
    arrayList.add(12);
    System.out.print(arrayList);
  }
 }

 class demo
 {
   public static void main(String[] args) 
   {
    ArrayList arrayList=new ArrayList();
    arrayList.add(1001);
    arrayList.add("Amit Jain");
    arrayList.add("21");
    System.out.print(arrayList);
   }
 }

import java.util.*;
class demo
{
  public static void main(String[] args) 
  {
    ArrayList<Integer> arrayList=new ArrayList<>();
    Scanner scan=new Scanner(System.in);
    System.out.println("Enter How Many Numbers");
    int n=scan.nextInt();
    System.out.printf("Enter %d Numbers",n);
    for(int i=1;i<=n;i++)
      arrayList.add(scan.nextInt());
    System.out.println(arrayList);
  }
 }

 class demo
 {
  public static void main(String[] args) 
  {
    ArrayList arrayList=new ArrayList();
    Scanner scan=new Scanner(System.in);
    System.out.println("Enter How Many Numbers");
    int n=scan.nextInt();
    System.out.printf("Enter %d Numbers",n);
    for(int i=1;i<=n;i++)
        arrayList.add(scan.nextInt());
    int s=0;
    for(int i=0;i<arrayList.size();i++)
        s=s+(int)arrayList.get(i);
    System.out.println("Sum is "+s);
  }
 }

import java.util.*;
class demo
{
  public static void main(String[] args) 
  {
    ArrayList<Integer> arrayList=new ArrayList<>();
    Scanner scan=new Scanner(System.in);
    System.out.println("Enter How Many Numbers");
    int n=scan.nextInt();
    System.out.printf("Enter %d Numbers",n);
    for(int i=1;i<=n;i++)
      arrayList.add(scan.nextInt());
    int s=0;
    for(int item:arrayList)
      if(item%2==0)
        s=s+item;
    System.out.println("Sum of even is "+s);
  }
}

import java.util.*;
class demo
{
  public static void main(String[] args) 
  {
    ArrayList<Integer> arrayList=new ArrayList<>();
    Scanner scan=new Scanner(System.in);
    System.out.println("Enter How Many Numbers");
    int n=scan.nextInt();
    System.out.printf("Enter %d Numbers",n);
    for(int i=1;i<=n;i++)
      arrayList.add(scan.nextInt());
    int c=0;
    for(int item:arrayList)
      if(item>0)
        c=c+1;
    System.out.println("Total Negative no. are "+c);
  }
}

class demo
{
  public static void main(String[] args) 
  {
    Vector vector=new Vector();
    Scanner scan=new Scanner(System.in);
    System.out.println("Enter How Many Numbers");
    int n=scan.nextInt();
    System.out.printf("Enter %d Numbers",n);
    for(int i=1;i<=n;i++)
      vector.add(scan.nextInt());
    int c=0;
    for(int i=0;i<vector.size();i++)
    { 
      int val=(int)vector.get(i);
      if(val%2==0)
        c=c+1;
    }
    System.out.println("Total even no. are "+c);
  }
}