package com.java.tricks;
import java.lang.reflect.Field;
public class ReverseString {
/**
* This method is used to reverse string without using any string class method.
*/
private static void reverseString(String value) {
try {
/** to access the private value[] array of String class. */
Field field = String.class.getDeclaredField("value");
/** Grant the access to access the field value. */
field.setAccessible(true);
/** Access the value array from the String class. */
char[] array = (char[]) field.get(value);
int i = 0; int j = array.length-1;
/** Reverse the array values to reverse it. */
while(i<j) {
char temp = array[i];
array[i] = array[j];
array[j] = temp;
i++; j--;
}
/** Set the reversed array into the String Object. */
field.set(value, array);
} catch (NoSuchFieldException | SecurityException |
IllegalArgumentException | IllegalAccessException e) {
System.err.println(e.getCause());
}
}
/**
* Driver method to reverse a String.
*/
public static void main(String[] args) {
String value = "geeksforgeeks";
System.out.println(value);
reverseString(value);
System.out.println(value);
}
}
