Update StringIterator.java

core-java-modules/core-java-strings/src/main/java/com/baeldung/stringIterator/StringIterator.java

@@ -1,14 +1,53 @@
 package com.baeldung.stringIterator;
 
+import java.text.*; 
+import java.util.*;
+
 public class StringIterator {
     public static void main(String[] args) {
         String str = "Hello, Baeldung!";
+        javaforLoop(str);
+        System.out.println();
         java8forEach(str);
+        System.out.println();
+        javaCharArray(str);
+        System.out.println();
+        javaRegexExp(str);
+        System.out.println();
+        javaCharacterIterator(str);
     }
-  
+
+    public static void javaCharArray(String str){
+        for (char c : str.toCharArray()) { 
+            System.out.print(c);
+        }
+    }
+
+    public static void javaforLoop(String str) {
+        for (int i = 0; i < str.length(); i++) {
+            char c = str.charAt(i);
+            System.out.print(c);
+        }
+    }
+
     public static void java8forEach(String str){
         str.chars().forEach(name -> {
             System.out.print((char) name);
         });
     }
+
+    public static void javaRegexExp(String str){
+        String[] characters = str.split(""); 
+        for (String c : characters) { 
+            System.out.print(c); 
+        }
+     }
+
+    public static void javaCharacterIterator(String str){
+        CharacterIterator it = new StringCharacterIterator(str);  
+        while (it.current() != CharacterIterator.DONE) { 
+            System.out.print(it.current()); 
+            it.next(); 
+        }
+    }
 }