• Java 实现字符串反转


    方法一:

    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));  
        }  
      
    }  
    View Code

    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+" ");  
            }  
        }  
    }  
    View Code

    如果描述改一下,输入一个字符串,例如“abcd”,输出"dcba"

    public static String reverse(String str){  
            return new StringBuilder(str).reverse().toString();  
        }
       public void test09() {  
            String str = "hello";  
      
            for (int i = str.length() - 1; i >= 0; i--) {  
                  
                char c = str.charAt(i);  
                  
                System.out.print(c);  
            }  
        } 
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  • 原文地址:https://www.cnblogs.com/Claire6649/p/6235916.html
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