Java program to find all substrings of a string

Java program to find substrings of a string :- This program find all substrings of a string and the prints them. For example substrings of "fun" are :- "f", "fu", "fun", "u", "un" and "n". substring method of String class is used to find substring. Java code to print substrings of a string is given below.

Java programing code

import java.util.Scanner;
 
class SubstringsOfAString
{
   public static void main(String args[])
   {
      String string, sub;
      int i, c, length;
 
      Scanner in = new Scanner(System.in);
      System.out.println("Enter a string to print it's all substrings");
      string  = in.nextLine();
 
      length = string.length();   
 
      System.out.println("Substrings of \""+string+"\" are :-");
 
      for( c = 0 ; c < length ; c++ )
      {
         for( i = 1 ; i <= length - c ; i++ )
         {
            sub = string.substring(c, c+i);
            System.out.println(sub);
         }
      }
   }
}

Download Substrings of a string program class file.

Output of program:

For a string of length n there will be (n(n+1))/2 non empty substrings and one more which is empty string. Empty string is considered to be substring of every string also known as NULL string.