how to change a character in a string in java code example

Example 1: how to change single character of a string in java

//short answer: you cannot individually change any specific character
//of a String in java. You can however do this:

String s1 = "This is a String";
String s2 = s1.substring(0, 8) + "o" + s1.substring(9);
System.out.println(s2);
//Prints "This is o String", replaced the 8th character with an o

Example 2: how to change a character in a string in java with ascii

import java.text.ParseException;
import java.util.Arrays;

/**
 * How to convert a String to ASCII bytes in Java
 * 
 * @author WINDOWS 8
 */

public class StringToASCII {

    public static void main(String args[]) throws ParseException {
        
        // converting character to ASCII value in Java
        char A = 'A';
        int ascii = A;
        System.out.println("ASCII value of 'A' is  : " + ascii);
        
        // you can explicitly cast also
        char a = 'a';
        int value = (int) a;
        System.out.println("ASCII value of 'a' is  : " + value);
        
        
        
        
        // converting String to ASCII value in Java
        try {
            String text = "ABCDEFGHIJKLMNOP";

            // translating text String to 7 bit ASCII encoding
            byte[] bytes = text.getBytes("US-ASCII");
            
            System.out.println("ASCII value of " + text + " is following");
            System.out.println(Arrays.toString(bytes));
            
        } catch (java.io.UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

}

Output
ASCII value of 'A' is  : 65
ASCII value of 'a' is  : 97
ASCII value of ABCDEFGHIJKLMNOP is following
[65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80]


Read more: https://javarevisited.blogspot.com/2015/07/how-to-convert-string-or-char-to-ascii-example.html#ixzz6k2vn7o4y

Example 3: java string replace character at position

String str = in.nextLine();	//Original String
char cr = in.next().charAt(0); // character to replace
int index = in.nextInt();	// Index where replaced
str = str.substring(0, index) + cr + str.substring(index + 1);// modified string

Example 4: java replace character in string

String s = "new String";
String replaced = s.replace("new","Test");
							  ^		 ^
                             old    new char

Example 5: replace character in string java

String str = ".............................."; 

        int index = 5; 
  
        char ch = '|'; 
 
        StringBuilder string = new StringBuilder(str); 
        string.setCharAt(index, ch); 

        System.out.println(string);

Example 6: how to replace a character with another character in a string in java

public class JavaExample{
   public static void main(String args[]){
	String str = new String("Site is BeginnersBook.com");

	System.out.print("String after replacing com with net :" );
	System.out.println(str.replaceFirst("com", "net"));

	System.out.print("String after replacing Site name:" );
	System.out.println(str.replaceFirst("Beginners(.*)", "XYZ.com"));
   }
}