How can one manually reverse a string in Java?

• A. Use the StringBuilder class
• B. Iterate through the string backwards
• C. Call the reverse() method of String class
• D. Convert the string to a character array and sort

Answer: (B)

To manually reverse a string in Java, one effective approach is to iterate through the string backwards. This method involves starting from the last character of the string and moving towards the first character, constructing a new string as you go.

In practical implementation, you can utilize a loop that begins at the string's length minus one (which refers to the last character) and decrements the index until it reaches zero, appending each character to a new string. For instance:

String original = "hello";

String reversed = "";

for (int i = original.length() - 1; i >= 0; i--) {

reversed += original.charAt(i);

}

This will effectively produce "olleh". The reason this is a valid method is that it leverages fundamental control structures and string operations in Java, making it a clear demonstration of manual reversal.

Other options might not yield a correct manual reversal. Utilizing the StringBuilder class is a valid approach for reversing a string, but it does not align with the idea of "manually" reversing it, as it relies on built-in methods. Calling the reverse() method of the String class specifically does not exist; one must use StringBuilder or a similar class to perform such