Question

Write a program in Java to store 20 different names and telephone numbers of your friends in two different Single Dimensional Arrays (SDA). Now arrange all the names in alphabetical order and display all the names along with their respective telephone numbers use selection sort technique.

Write a program to accept 10 names in a Single Dimensional Array (SDA). Display the names whose first letter matches with the letter entered by the user.

Sample Input: Aman Shahi
Akash Gupta
Suman Mishra and so on --------
Sample Output: Enter a letter
                            A
                            Aman Shahi
                            Akash Gupta
                            --------------

Answer 1

1. import java.util.*;
   public class SQ26_A
   {public static void main(String args[]){
   Scanner ob = new Scanner(System.in);
   String tmp, n[] = new String[20];
   long t, ph[] = new long[20];
   int i, j;
    
   
   INPUT LOOP FOR NAME & PHONE
   for (i = 0; i < n.length; i++)
   {
   System.out.print("Name: ");
   n[i] = ob.next();
   System.out.print("Phone num: ");
   ph[i] = ob.nextLong();
   }
   
   //LOOP TO SORT NAMES IN ALPHABETICAL ORDER
   int min;
   for (i = 0; i < n.length - 1; i++)
   {
      min = i;
      for (j = i + 1; j < n.length; j++)
      { if (n[j].compareTo(n[min]) < 0)
      min = j;
      }
   
      tmp = n[i];
      n[i] = n[min];
      n[min] = tmp;
   
      t = ph[i];
      ph[i] = ph[min];
      ph[min] = t;
   }
   System.out.println("\n TELEPHONE DIRECTORY");
   for (j = 0; j < n.length; j++)
   System.out.println(n[j] + "\t\t" + ph[j]);
   }}

2. import java.util.*;
   public class SQ26_B
   {public static void main(String args[]){
   Scanner ob = new Scanner(System.in);
   String n[] = new String[10];
   char ch;
   int i;
   
   // INPUT LOOP FOR NAME
   for (i = 0; i < n.length; i++)
   {System.out.print("Name: ");
   n[i] = ob.next();
   }
   
   // INPUT OF ALPHABET
   System.out.println("Enter the letter to be searched");
   ch = ob.next().charAt(0);
   
   // INPUT OF ALPHABET
   System.out.println("Enter the letter to be searched");
   ch = ob.next().charAt(0);
   
   // OUTPUT LOOP - NAMES MATCHING WITH THE ALPHABET
   for (i = 0; i < n.length; i++)
   {
   if (ch == n[i].charAt(0))
   System.out.println(n[i]);
   }}}