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

Java programming 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:
Output of Java program fo find all substrings of a string

For a string of length n, there are (n(n+1))/2 non empty substrings and an empty string. Empty or NULL string is considered to be a substring of every string.