Question

Change the code to sort list of strings without using any pre-defined functions

Here is my code:

    int n;
    String temp;
    Scanner in = new Scanner(System.in);
    System.out.print("Enter number of names you want to enter:");
    n = in.nextInt();
    String names[] = new String[n];
    Scanner s1 = new Scanner(System.in);
    System.out.println("Enter all the names:");
    for(int i = 0; i < n; i++){
        names[i] = s1.nextLine();
    }
***CHANGE THIS PART***
    for (int i = 0; i < n; i++){
        for (int j = i + 1; j < n; j++){
            if (names[i].compareTo(names[j])>0) {
                temp = names[i];
                names[i] = names[j];
                names[j] = temp;
            }
        }
    }
*** I WANT TO SORT WITHOUT USING ".compareto()" OR ANY OTHER PRE-DEFINED FUNCTION***
    System.out.print("Names in Sorted Order:");
    for (int i = 0; i < n - 1; i++){
        System.out.print(names[i] + ",");
    }
    System.out.print(names[n - 1]);

Answer 1

Answer:-

Hello, I have modified the given program so as it can sort the array of Strings without using any predefined function. Please find it below.

Here I have written a user-defined function compareString which is used for comparing two strings. And from the main function, we are calling this compartString function for comparing the Strings of names array.

JAVA CODE:-

import java.util.Scanner;
class Solution
{
   /* compareString function for comparing two strings*/
   static int compareString(String a,String b)
   {
       a=a.toUpperCase();
       b=b.toUpperCase();
       /*Loop for visiting each character of Strings*/
       for(int i=0;i<a.length()&&i<b.length();i++)
       {
           /*Checking if the character at index i in both strings are equal or not*/
if(a.charAt(i)==b.charAt(i))
{

}
/* If String a is greter than String b then it will return 1*/
else if(a.charAt(i)>b.charAt(i))
{
   return 1;
}
/* If String a is lesser than String b then it will return -1*/
else
{
   return -1;
}
       }
   /*If both the Strings are equal then it will return 0.*/
       return 0;
   }

   public static void main(String [] args)
   {
int n;
String temp;
Scanner in = new Scanner(System.in);
System.out.print("Enter number of names you want to enter:");
n = in.nextInt();
String names[] = new String[n];
Scanner s1 = new Scanner(System.in);
System.out.println("Enter all the names:");
for(int i = 0; i < n; i++){
names[i] = s1.nextLine();
}
for (int i = 0; i < n; i++){
for (int j = i + 1; j < n; j++){
if (compareString(names[i],names[j])==1) {
temp = names[i];
names[i] = names[j];
names[j] = temp;
}
}
}
System.out.print("Names in Sorted Order:");
for (int i = 0; i < n - 1; i++){
System.out.print(names[i] + ",");
}
System.out.print(names[n - 1]);

   }
}

Screenshot of Code:-

Please refer to the screenshots of the code for properly understanding the indentation of the code.

Screenshot 1:

Screenshot 2:

OUTPUT:-

NOTE:- compareString is not any predefined function. We have defined this function in our code.

I hope it would help.

Thanks!