ArrayList - Converting ArrayList to String Array

// ArrayList

// ArrayList to String array

/*

Write a java program to convert ArrayList to String array

*/

import java.util.*;

class ALtoSA

{

     public static void main(String as[])

     {

          // Creating ArrayList

          ArrayList <String>al = new ArrayList<String>();

          Scanner s = new Scanner(System.in);

         

          System.out.print("Enter number of strings : ");

          int N = s.nextInt();

         

          for(int i=0;i<N;i++)

          {

              System.out.print("Enter string : "); 

              String str = s.next();

              al.add(str);

          }

         

          System.out.println("Elements in ArrayList are : "+al);      

         

          // Creating a String array

          String[] SA = new String[al.size()];

         

          // Converting ArrayList to String Array

          SA = al.toArray(SA);

         

          System.out.println("Elements in String array : ");

          for(String str:SA)

              System.out.println(str);

     }

}

ArrayList - converting string array to ArrayList

// ArrayList

// String array to ArrayList

/*

Write a java program to convert String array to ArrayList

*/

import java.util.*;

class SAtoAL

{

     public static void main(String as[])

     {

          // Creating a String array

          String[] SA = new String[]{"CSE", "IT","ECE","ECE"};

         

          // Converting string array to ArrayList

          ArrayList<String> al = new ArrayList<>(Arrays.asList(SA));

         

          System.out.println("Elements in ArrayList are : "+al);

     }

}

ArrayList - String operations

/*

     Write a program to perform string operations using Array List.

     Write functions for the following

          Append - add at end

          Insert – add at particular index

          Search

          List all string starts with given letter

*/

// ArrayList

import java.util.*;

class ArrList

{

     public static void main(String as[])

     {

          ArrayList <String>AL = new ArrayList<String>();

          Scanner s = new Scanner(System.in);

         

          while(true)

          {

              System.out.println("\n1 - Append \t2 - Insert \t3 - Search \t4 - List \t5 - exit");

             

              int ch;

              System.out.print("Enter choice : "); 

              ch = s.nextInt();

              if(ch==1)

              {

                   System.out.print("Enter data : ");

                   String str = s.next();

                  

                   AL.add(str);

              }

              else if(ch==2)

              {

                   System.out.print("Enter position : ");

                   int pos = s.nextInt();

                   System.out.print("Enter data : ");

                   String str = s.next();

                   AL.add(pos,str);

              }

              else if(ch==3)

              {

                   int i;

                   System.out.print("Enter data to search : ");

                   String str = s.next();

                  

                   String str_arr[] = new String[AL.size()];

                   str_arr = AL.toArray(str_arr);             

                  

                   for(i=0;i<AL.size();i++)

                        if(str.equalsIgnoreCase(str_arr[i]))

                        {

                             System.out.println("String "+str+" found at position "+(i+1));

                             break;

                        }

                   if(i==AL.size())

                        System.out.println("String not found.");

              }

              else if(ch==4)

              {

                   System.out.println("Elements in ArrayList are : "+AL);

                  

                   int i;

                   System.out.print("Enter starting character : ");

                   char c = (s.next()).charAt(0);

                  

                  

                   String str_arr[] = new String[AL.size()];

                   str_arr = AL.toArray(str_arr);             

                   System.out.println("String atarting with character "+c+" are : ");

                   for(i=0;i<AL.size();i++)

                        if(str_arr[i].charAt(0)==c)

                             System.out.println(str_arr[i]);

              }

              else if(ch==5)

                   System.exit(0);

              else

                   System.out.println("Invalid choice");

          }

     }

}