Java program to find and print all special characters with their positions in a string

Program to find special characters in a string

In this section, you will learn how to find special characters from a string in Java along with counting the total number of special characters with their positions in a given string.

Let's try to create a simple example :

  ➤ Example : FindSpecialChar.java;

1. import java.util.regex.Matcher;
   import java.util.regex.Pattern;
   import java.util.Scanner;
   
   class FindSpecialCharactetrs {
       public static void main(String args[]) {
           Scanner input = new Scanner(System.in);
           String str;
           
           System.out.print("\nEnter a string : ");
           str = input.nextLine();
           
           Pattern string_patterns = Pattern.compile("[^a-z0-9 ]", Pattern.CASE_INSENSITIVE);
           Matcher string_matcher = string_patterns.matcher(str);
           
           System.out.println("\n\n\t______________ OUTPUT ______________");
           System.out.println("\nYour string is : "+str);
       
           int count = 0;
           while(string_matcher.find()) {
             count = count + 1;
             System.out.println("\tposition "+string_matcher.start() +": "+ str.charAt(string_matcher.start()));
           }
           System.out.println("\nThere are "+count+" special characters");
           System.out.println("\n\t------------------------------------");
       }
   }

 import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Scanner;

class FindSpecialCharactetrs {

    public static void main(String args[]) {
        Scanner input = new Scanner(System.in);  
        String str;

        System.out.print("\nEnter a string : ");
        str = input.nextLine(); 

        Pattern string_patterns = Pattern.compile("[^a-z0-9 ]", Pattern.CASE_INSENSITIVE);  
        Matcher string_matcher = string_patterns.matcher(str);  

        System.out.println("\n\n\t______________ OUTPUT ______________");
        System.out.println("\nYour string is : "+str);

        int count = 0;

        while(string_matcher.find()) {
            count = count + 1;
            System.out.println("\tposition "+string_matcher.start() +": "+ str.charAt(string_matcher.start()));
        }

        System.out.println("\nThere are "+count+" special characters");
        System.out.println("\n\t------------------------------------");

    }
}
 

Output 1:

• Enter a string : `Welcome to #coderwebsite && "j@v@" is @m@zing programming l@ngu@ge`!

•  

• ______________ OUTPUT ______________

• Your string is : `Welcome to #coderwebsite && "j@v@" is @m@zing programming l@ngu@ge`!

•   position 0: `

•   position 12: #

•   position 26: &

•   position 27: &

•   position 29: "

•   position 31: @

•   position 33: @

•   position 34: "

•   position 39: @

•   position 41: @

•   position 60: @

•   position 64: @

•   position 67: `

•   position 68: !

• There are 14 special characters

• ------------------------------------

Output 2:

• Enter a string : Welcome to coderwebsite

•  

• ______________ OUTPUT ______________

•  

• Your string is : Welcome to coderwebsite

• There are 0 special characters

• ------------------------------------

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