描述:给我一个字符串,例如I love java,输出: java love I
方法一
[java] view plaincopy- public class StringReverse {
- public void swap(char[] arr, int begin, int end) {
- while(begin < end) {
- char temp = arr[begin];
- arr[begin] = arr[end];
- arr[end] = temp;
- begin++;
- end--;
- }
- }
- //I love java
- public String swapWords(String str) {
- char[] arr = str.toCharArray();
- swap(arr, 0, arr.length - 1);
- int begin = 0;
- for (int i = 1; i < arr.length; i++) {
- if (arr[i] == ' ') {
- swap(arr, begin, i - 1);
- begin = i + 1;
- }
- }
- return new String(arr);
- }
- public static void main(String[] args) {
- String str = "I love java";
- System.out.println(new StringReverse().swapWords(str));
- }
- }
- public class StringReverse {
- public void swap(char[] arr, int begin, int end) {
- while(begin < end) {
- char temp = arr[begin];
- arr[begin] = arr[end];
- arr[end] = temp;
- begin++;
- end--;
- }
- }
- //I love java
- public String swapWords(String str) {
- char[] arr = str.toCharArray();
- swap(arr, 0, arr.length - 1);
- int begin = 0;
- for (int i = 1; i < arr.length; i++) {
- if (arr[i] == ' ') {
- swap(arr, begin, i - 1);
- begin = i + 1;
- }
- }
- return new String(arr);
- }
- public static void main(String[] args) {
- String str = "I love java";
- System.out.println(new StringReverse().swapWords(str));
- }
- }
方法二:(利用jdk提供的方法)
- public class Main {
- public static void main(String[] args) {
- Scanner sc = new Scanner(System.in);
- String str = sc.nextLine();
- String[] sArr = str.split(" ");//I love java
- List<String> list = new ArrayList<String>();
- list = Arrays.asList(sArr);
- // for(int i=0;i<sArr.length;i++){
- // list.add(sArr[i]);
- // }
- Collections.reverse(list);
- for(String word:list){
- System.out.print(word+" ");
- }
- }
- }
- public class Main {
- public static void main(String[] args) {
- Scanner sc = new Scanner(System.in);
- String str = sc.nextLine();
- String[] sArr = str.split(" ");//I love java
- List<String> list = new ArrayList<String>();
- list = Arrays.asList(sArr);
- // for(int i=0;i<sArr.length;i++){
- // list.add(sArr[i]);
- // }
- Collections.reverse(list);
- for(String word:list){
- System.out.print(word+" ");
- }
- }
- }
当然了方法很多,这里我提供一个jdk自带的方法,比较简单
- public static String reverse(String str){
- return new StringBuilder(str).reverse().toString();
- }
- public static String reverse(String str){
- return new StringBuilder(str).reverse().toString();
- }
- @Test
- public void test09() {
- String str = "hello";
- for (int i = str.length() - 1; i >= 0; i--) {
- char c = str.charAt(i);
- System.out.print(c);
- }
- }
- @Test
- public void test09() {
- String str = "hello";
- for (int i = str.length() - 1; i >= 0; i--) {
- char c = str.charAt(i);
- System.out.print(c);
- }