java中的字符串反转

package stringTest;public class StringDemo3 {public static void main(String[] args) {StringDemo3 sd3 = new StringDemo3();String str = "abcdefg";System.out.println(sd3.reverseString(str)); //打印结果：gfedcba}/** * 数组中的元素的交换 * */void swap(char[] arr, int index1, int index2){char tmp;tmp = arr[index1];arr[index1] = arr[index2];arr[index2] = tmp;}/** * 数组的反转 * */void reverseArr(char[] arr){for (int start = 0, end = arr.length-1; start < end; start++, end--){swap(arr, start, end);}} /** * 将字符串反转，思路： * 1、将字符串变为数组 * 2、将数组反转 * */String reverseString(String str){char[] arr = str.toCharArray();//将字符串变为数组reverseArr(arr); //数组反转return new String(arr);}}