how to iterate over a string in java

To iterate over the characters of a string in Java, you can use a for loop or the for-each loop.

Here is an example of how you can use a for loop to iterate over the characters of a string and print them:

String str = "Hello World";

for (int i = 0; i < str.length(); i++) {
    char c = str.charAt(i);
    System.out.println(c);
}

This will print each character of the string on a separate line.

Here is an example of how you can use a for-each loop to achieve the same result:

String str = "Hello World";

for (char c : str.toCharArray()) {
    System.out.println(c);
}

You can also use the Iterator class to iterate over the characters of a string, like this:

String str = "Hello World";

Iterator<Character> iterator = str.chars().mapToObj(c -> (char) c).iterator();
while (iterator.hasNext()) {
    char c = iterator.next();
    System.out.println(c);
}

Keep in mind that the String class is immutable, which means that the characters of a string cannot be modified directly. If you need to modify the characters of a string, you can use the StringBuilder class or the String.replace method.