space replacement，replacement,Write a meth

space replacement，replacement,Write a meth

Write a method to replace all spaces in a string with '%20'. Assume string hassufficient space at end of string to hold additional characters, and thatyou're given a true length of a string. I used the books code, implementingthe solution in Java using a character array (given the fact that Java Stringsare immutable)

import java.util.Arrays;public class OnePointFour {        private static String replaceSpace(String a, int b){            char[] char_sets = a.toCharArray();            int len = a.length()-1;            for(int i=b;i>0;i--){                if(char_sets[i] != ' '){                    char_sets[len] = char_sets[i];                    len = len-1;                    }                else{                    char_sets[len] = '0';                    char_sets[len-1] = '2';                    char_sets[len-2] = '%';                    len = len - 3;                }            }            return Arrays.toString(char_sets);            //return char_sets.toString();            //返回的结果：[d, d, b, %, 2, 0, %, 2, 0, a, c, e]，不知道为什么        }        public static void main(String[] args){            System.out.print(replaceSpace("ddb  ace    ", 7));        }}//该片段来自于http://byrx.net